What I find ironic is all the people in this thread who play inviable characters that I would probably three stock effortlessly. Are you really in a position to look down on others? Being unskilled is relative. You're also a noob if you're not playing one of the top 10 characters in the game (those who place well without these characters are obviously exceptions). I bet that if I were to sit down with 80% of you, I'd be able to just roll through your stocks with my Marth/MK/Snake/Falco, and you'd never win. Then I'd think to myself, "Why am I wasting my time playing with these noobs?"
That being said, I greatly enjoy playing with noobs. I love to play, and I love to teach. When my opponent isn't interested in learning the competative rulesets and ways to play, it's okay. To me, that makes perfect sense. Why would a player who has no intention of ever competing in this game play by the competative ruleset. Items can be pretty fun. And while items do sometimes provide random advantages, it doesn't really imbalance matches frequently. Just don't cry if you lose one match because something stupid happens, and be secure in your skill. I smile when someone blatently worse than me gets happy because they get a kill off something stupid. To me, it's a sign of respect that they're so happy to be able to take one kill or game off me. I still don't beat M2k very often when items are turned on, and though I haven't played ADHD very often with items turned on, I'm willing to bet that his win percentage would increase. I think items are likely to increase the gap between players, as opposed to balancing out the game. I once K.O.ed a noob three times in under a minute using no gimps, with no items on.
Often, when playing people much below my skill level, it gives me a chance to train up other characters. I learned how to play Zelda, Snake, Kirby, Shiek, and improved my Marth, MK, Falco, Ike, Mario, Link, and other random characters. Now, I'm working on my Diddy Kong, and Captain Falcon. None of you can deny that winning is an encouraging event, so training up new characters and still winning is very effective.
Also, if I'm playing multiple noobs at once, I teach them how to play competative doubles, to teach them discipline and teamwork. These skills put them in the mindset to be ready to learn in singles. I rotate the teams, playing with each player, so everyone gets a chance at winning (when they team with me). Sometimes, for the lulz, I set it to three against one, for a slight challenge.
Don't limit yourself. You shouldn't really be having difficulty dealing with noob tactics if you aren't a noob yourself. I'll be ****ed if a rolling Lucario frustrates me. Since noobs are so . . . noobish, you should be able to generate massive damage off good attack strings, and it gives you a good chance to develop your offense.
tl;dr
Don't knock noobs.