Adumbrodeus, I understand the metaphor about infinite invincibility, and also that there are other characters that are capable of doing the same thing... Albeit likely only a few- example being Wario... You ever get camped by a wario on battlefield while using Zelda? I can guarantee you that it's impossible for her to touch him if done right.
I don't see how banning it for MK can be justified when others can practically do the same thing. And this is just one of my reasons. (It'd take too long to explain them all right now, so I'll argue them as they come up. Dx)
And you'd be surprised how much research I've done on this. *hint* *hint*
edit: this post didn't come off as smoothly as I would have liked. Perhaps I should wait till I have regular computer access for me to post much about this subject.