Why the hell is this thread still alive? I remember Mookierah winning it way back in the first 10 pages, like months ago.
Anyways, regarding bans:
The goal of a ban is to remove strategies, characters, items, or situations that reduce competitions to only that and possibly a few other options. Why? Because as much as playing to win means utilizing everything at your disposal, regardless of fairness, any good competitive game NEEDS to retain some kind of skill gap.
Simply put, the more consistently a more skilled and knowledgeable player wins over a lesser one, the better. In Melee, the top players in the country consistently place at the top, with Mew2King still winning most of his tourneys. That's an example of a good competitive game.
If there's things or tactics that reduce the game to only that element in competition, then worse players will have a higher probability of beating better ones due to lack of variety and learning curve. So those things or tactics warrant a ban.
However, banning is something that competitive communities AVOID AT ALL COSTS unless it is absolutely needed, such as I just pointed out. Even if it retracts from play a great deal, like the limited viability of characters other than Snake, MK, and D3 among talented players, it still must be kept an option, or else streams of needless banning will ensue.
Competitive play in Brawl has never even come close to being reduced to infinites. So, no ban.
These last two paragraphs are kind of poor and random, I just mentioned that stuff for the hell of it.
[And lets say that some ridiculous infinite was found that could combo a an enemy from zero percent to death, without the user needing to account for DI, without requiring precise timing or inputs, with no need for modifications based on the current situation, and available to even the weakest player. This, in fact, may not even need a ban. With something like this, likely a "soft ban" would appear, where really skilled players have an unwritten rule that the combo is crap and ruins competitive play and they all refuse to use it. In the event that a new player, with no sense of honor, tries to win a tourney with this tactic, he would likely fall flat on his face, destroyed by much better opponents who can avoid the beginning of the fatal combo.
Zero to deaths existed in Melee, in countless shapes and forms, but they were results of very taxing technical play, mindgames, tech chasing, DI prediction, and luck. Yet, if you watch pro matches, they happen very, very often. These aren't even up for ban discussion because they're just evidence of player skill and execution. A lesser case of this is the IC infinite grab combos that so many complain about. It may not be near as hard as zero-to-deathing a pro player in Melee, but it still requires a set-up, difficult timing, and some technical skill.]