... lol well if we're gonna list the reasons why he's bad I can pull out a whole list. I dropped Luigi because I used to play NAKAT all the time (who recently just beat Boss with MK not too long ago at Inui's Great Revival)
Look guys, Luigi has a problem getting camped, you'll realize this when getting camped haaard by ROB's, Foxes and Snakes that Luigi really can't do anything to stop them except running at them and trying to BS and approach. Fireball doesn't work to be that good of a projectile at all.
Another problem is Luigi's mobility in the air... once Luigi gets popped into the air how is he going to land when he has no air mobility and even his fast fall is slow..
If you want to get specific Metaknight really is the death matchup that Luigi's complain about,
mach tornado destroys every single one of his options except if the MK is being predictable with it; but no good experienced MK will tornado when they can be punished. Then we add Luigi's traction problem and bla bla bla....
Luigi can't get in on players who play safe/reactionary. If you play aggro, then maybe Luigi can BS an approach while you weren't looking and F u up, until then the character can really just stand in one place and wait for Luigi to do something lol.
Sorry to say, but Luigi can't camp as well as most characters and he can't approach as well either... so what does he have going for him except stupid kill power and good aerials? Nothing.