You only think it's dull and broken because you don't bother to play it the same way you would look at Melee or Smash 64. You go in playing Brawl knowing that it doesn't have the techs and available options that Melee has, and thus you find it empty and unfulfilling. Anybody who's entering a game/function/event expecting it to be crap will look at the downfalls and say it's crap. Fine, think of it as you want, but other people, like myself, find this game very competitive. The accessability to high-level gaming through its easier controls, not to mention its online capabilites, could drive more people into Brawl than having a game fileld with advanced techs coming out the wazoo.
Melee may have a higher degree of competitiveness, but most people play to win. I certainly don't think that Brawl is too shallow that winning only makes a hollow feeling, and most people don't. If you think you're too good to play Brawl, then play Melee.