I had actually talked to TGM about the issues I had with the tournament rules before,(though I didn't originally realize they were tournament rules and not just his own preference) and I'll sum up my points here, cause I can't remember whether it was in a private message or simply in a public post:
To put simply, I can understand the issues with the moving stages and setting item usage appearance to heavy. You reach a point where you aren't demonstrating your skill and knowledge of a character, but merely your skill at keeping up with how the stage moves and grabbing items and chucking them.
Stages may have certain exploits to them, but avoiding or using those exploits is, in my eyes, simply another of the many skill sets that distinguish Brawl from other fighter games. If there's a stage where you can get pinned up against a wall for 999% damage, then don't get close to a wall to allow that to happen. being able to guide your opponent into a position where you can execute such a devastating maneuver requires a great deal of strategy, and should be recognized rather than buried.
This goes just as much for items that appear, smash balls, trophies, pokeballs and anything else. Being able to react to an item appearing, getting to it first, using it accurately if acquired, and also being able to avoid it if acquired by the opponent, are completely valid skills and strategies that shouldn't just be shoved aside. I believe I have personally managed to avoid the effects of nearly every single trophy, pokeball and smash ball at some point in the battles i have had, including that swordswoman from fire emblem(I can't remember her name) that usually ends up as an instant KO.
To me, every other fighting game out there is a sport, nothing more than that. Brawl is different. It is perhaps the is the single most complete form of "combat" and "battle" that I have ever experienced.
The very basic difference of having a damage counter rather than a health bar is the most obvious difference. A health bar is a predetermined point at which the battle is decided. Once a certain number of points are reached, the victory is decided and the next round starts.
However with Brawl, your tenacity is the ultimate deciding factor, there is no predetermined point at which you have lost. You keep fighting until you can no longer come back, and even after you've won a round, you still have to continue on with what damage you've taken.
Different moves and styles exist, and only through learning them all can you be able to predict your opponent's attacks. more than just your opponent, you must be able to adapt and use your environment to your best advantage, and also adapt to cases of chance giving a possible advantage to one opponent or the other.