K...heres what i think, if the infinite is EASY and is TOTALLY INESCAPABLE NO MATTER WHAT, the HOST of the tournament decides whether to ban or not, what %s its up to, or not to ban it at all. For the Dedede infinite chaingrabs on samus, mario, whatever, the host will decide to allow to a certain percent, since you can't erally ban a grab....or hell, PICK A DIFFERENT CHARACTER. There is NO TOTALLY ESCAPABLE INFINITE besides walled laser lock, but then again, there are no infinite walls that never leave, so there are NO real infinites (not sure about IC back throw thingy, i don't know if you can get out at high %s) Since there are NO infinites, you have to learn who can do what to whom, and which character you shouls use against it, if you main mario and you are playing against a dedede, use pikachu, zelda/shiek, or whoever else falls, so you can't get grabbed again. Seriously, it all boils down to the tournament host deciding to ban or not. So if you think that infinites are ban, ban them among your friends or your tournaments if you host one, don't ***** to everybody else "omg its so cheap and gay ban it!"
Infinite comboes are normally hard to pull off, and require a large amount of skill/timing to pull off. And as i said earlier, there are no 100% cannot get out of infinites.