The term scrub is thrown around a lot, and different people mean different things by it. Some people just mean "players who are terrible at the game", but that's not quite accurate to the "true" definition. Generally, a scrub is someone who is not only awful at the game in question but awful specifically because he has a bad mindset. Usually it refers to players who have the belief that certain tactics are "cheap" or "gay" or whatever term you prefer that is a way of saying "that is really good at winning games but you shouldn't do it anyway!". Being a scrub is bad because, with few exceptions, scrubs never improve. Improving means changing how you do things usually, and scrubs refuse to change.
Typically among fighting game communities, the term scrub is put on people who want to either forbid or disapprove of things. Like, people who complain about fireball spamming or who think certain characters shouldn't be used or that sort of thing. Yes, I know Akuma is banned in Street Fighter Super Turbo, but the term "scrub" isn't what you'd use to refer to someone who wants to allow him. "Misinformed" would be a better label since Akuma completely destroys that game. It's really ironic that some Smash Bros players have taken to calling players who want to allow assorted things (widely disliked stages, items, Meta Knight's IDC, etc.) as "scrubs" though it's somewhat understandable; I've seen a lot of arguments that degenerate somewhat along these lines:
New Person: No stages should be banned!
Older Person: Stages like the Temple obviously have to be banned.
New Person: I love the Temple! Why?
Older Person: Among other reasons, faster characters can run forever from slower characters, forcing a win by time if they have the lead (which is easy for a fast character like Fox to attain with his laser).
The argument sometimes goes off on a tangent here about not using a timer alongside the stock matches, but that leads into matches that never end. Eventually you get to this point:
New Person: You shouldn't just run anyway. [This is said in a variety of ways]
Older Person: Why not?
New Person: It's not fun/it's not what was intended/it's cheap/etc.
Older Person: Sure, but in a tournament with money on the line, you do what it takes to win. The tournament would be a joke if that were running forever on the Temple, so we ban the Temple.
At this point, the New Person is really unpredictable, but they very often propose rules that are in reality far more restrictive on the players than just banning the Temple. Even though they initially proposed looking at a wider array of things in the game (misinformed perhaps, but not scrubby), they ended up acting like scrubs when the broken tactics were proposed.
I'm not going to judge you personally since I really don't know you, but if you're like the countless people I've seen post things very much like you did, you probably just don't know a lot about how smash bros develops at higher levels. Like, items are really not something you can just allow; even item standard play (a niche movement of players who want to use items) turns off about half of the items and puts the spawn rate on low. This game isn't really a decent competitive game unless you at the very least really restrict items (like ISP does), and really, it's best if you just turn them off altogether (which is easy to justify since restricting them heavily was already necessary). The thing is, it's only clear how items make the game really inconsistent once you're good enough to be consistent without them. Likewise with certain stages like the Temple, I think most players who favor those sorts of stages just don't think about doing the various things that ruin the level. The biggest thing about getting better is finding the best tactics so it's understandable that players who have not begun to walk the path of getting legitimately better would miss things, but the fact remains that it needs to be banned and the argument won't go well for people who can't understand why.
To be friendly, I'll offer you the friendly advice that you might want to lurk for a bit (not post much but read a lot) to pick up on some things. Just learn about the game and try to understand why a lot of things are the way they are (some of the way things are done is historical with little real logic behind it, but a lot more is based on contemporary realities). Like, try to understand why people want items off and why even the people like me who want to allow as many stages as possible agree that some stages need to be banned. Getting engaged in the community is always great, but you want to make sure you don't argue about things you don't understand.
About Luigi's Mansion, I'm not sure why people get hit by these ceiling things so much. You can shield the Mach Tornado, and most of the stage is not under a ceiling. My games there against Meta Knight suggested to me that you just don't stand under the ceilings more than you have to, and you can just shield the Mach Tornado to either totally negate the damage or at least greatly reduce it (only getting hit by the last few hits is not a big deal). I'm of course only a product of my own experiences, but just plain not taking huge risks and actually stopping to think about mansion destruction even when under pressure and actually being stubborn about not chasing people under roofs seems to really abate the course. Luigi's Mansion is pretty much always allowed in my region, and we just don't have problems with it (though it's a popular target of personal player bans and definitely has a big crowd that just plain doesn't like it). Ceiling stuff happens sure, but it's not like it happens without the victim making a mistake or two first.
Typically among fighting game communities, the term scrub is put on people who want to either forbid or disapprove of things. Like, people who complain about fireball spamming or who think certain characters shouldn't be used or that sort of thing. Yes, I know Akuma is banned in Street Fighter Super Turbo, but the term "scrub" isn't what you'd use to refer to someone who wants to allow him. "Misinformed" would be a better label since Akuma completely destroys that game. It's really ironic that some Smash Bros players have taken to calling players who want to allow assorted things (widely disliked stages, items, Meta Knight's IDC, etc.) as "scrubs" though it's somewhat understandable; I've seen a lot of arguments that degenerate somewhat along these lines:
New Person: No stages should be banned!
Older Person: Stages like the Temple obviously have to be banned.
New Person: I love the Temple! Why?
Older Person: Among other reasons, faster characters can run forever from slower characters, forcing a win by time if they have the lead (which is easy for a fast character like Fox to attain with his laser).
The argument sometimes goes off on a tangent here about not using a timer alongside the stock matches, but that leads into matches that never end. Eventually you get to this point:
New Person: You shouldn't just run anyway. [This is said in a variety of ways]
Older Person: Why not?
New Person: It's not fun/it's not what was intended/it's cheap/etc.
Older Person: Sure, but in a tournament with money on the line, you do what it takes to win. The tournament would be a joke if that were running forever on the Temple, so we ban the Temple.
At this point, the New Person is really unpredictable, but they very often propose rules that are in reality far more restrictive on the players than just banning the Temple. Even though they initially proposed looking at a wider array of things in the game (misinformed perhaps, but not scrubby), they ended up acting like scrubs when the broken tactics were proposed.
I'm not going to judge you personally since I really don't know you, but if you're like the countless people I've seen post things very much like you did, you probably just don't know a lot about how smash bros develops at higher levels. Like, items are really not something you can just allow; even item standard play (a niche movement of players who want to use items) turns off about half of the items and puts the spawn rate on low. This game isn't really a decent competitive game unless you at the very least really restrict items (like ISP does), and really, it's best if you just turn them off altogether (which is easy to justify since restricting them heavily was already necessary). The thing is, it's only clear how items make the game really inconsistent once you're good enough to be consistent without them. Likewise with certain stages like the Temple, I think most players who favor those sorts of stages just don't think about doing the various things that ruin the level. The biggest thing about getting better is finding the best tactics so it's understandable that players who have not begun to walk the path of getting legitimately better would miss things, but the fact remains that it needs to be banned and the argument won't go well for people who can't understand why.
To be friendly, I'll offer you the friendly advice that you might want to lurk for a bit (not post much but read a lot) to pick up on some things. Just learn about the game and try to understand why a lot of things are the way they are (some of the way things are done is historical with little real logic behind it, but a lot more is based on contemporary realities). Like, try to understand why people want items off and why even the people like me who want to allow as many stages as possible agree that some stages need to be banned. Getting engaged in the community is always great, but you want to make sure you don't argue about things you don't understand.
About Luigi's Mansion, I'm not sure why people get hit by these ceiling things so much. You can shield the Mach Tornado, and most of the stage is not under a ceiling. My games there against Meta Knight suggested to me that you just don't stand under the ceilings more than you have to, and you can just shield the Mach Tornado to either totally negate the damage or at least greatly reduce it (only getting hit by the last few hits is not a big deal). I'm of course only a product of my own experiences, but just plain not taking huge risks and actually stopping to think about mansion destruction even when under pressure and actually being stubborn about not chasing people under roofs seems to really abate the course. Luigi's Mansion is pretty much always allowed in my region, and we just don't have problems with it (though it's a popular target of personal player bans and definitely has a big crowd that just plain doesn't like it). Ceiling stuff happens sure, but it's not like it happens without the victim making a mistake or two first.