^^^
Items just suck.
I'm still pondering over the ignorant "Not using items unballences a fight." thing.
Thats just...weird.
It's not as ignorant as you think. Why did the tiers turn out the way they did? Because they were based on JUST character strengths and such, and had nothing to do with items. If items were used, I think Bowser (for example) would see a surge up to a higher tier, simply because whenever he gets a Bob-omb, or any explosive item, he can hit both himself and the other player, and he won't fly very far at all. All sorts of new strategies would sprout up concerning how items aid Bowser's ledge guarding, for example. Really, I think items tend to equalize the tiers in the general case, not by taking away skill, but by making people choose, say, when to fire the Super Scope at Falco. Or whether to try to KO someone with the Home Run Bat, or simply chuck it at them.
To say that no items unbalances a fight is the same thing as saying that items tend to make the gaps between tiers less pronounced. This is, in general, a good thing.
You have to realize, also, that the reason items are banned in tourneys is strictly because of the randomly exploding crates, barrels, and capsules that cannot be turned off. Were it not for those, there would be no justification for not using items (non-broken items) in tourneys. I suppose there is a small amount of luck involved, but items contribute, on the whole, much more strategy than luck.
I agree with user_name in saying that Heart Containers, Starmen, and Maxim Tomatoes are broken, and I would hesitate to allow the Hammer or Food as well. As far as other items, there are a couple I could go either way on.
Brawl will not be Melee 2.0. Be prepared to use items, since they deepen the metagame as much as any of the advanced techniques, and they probably won't be turned off unless there is a similar problem in Brawl as in Melee.