Okay... here are my opinions on this matter...
Brawl is competitive, no matter what way you look at it. There's plenty of gamers who pay more attention to Brawl, rather than Melee. The reason why, is because it's the "new thing". And it's slower, and more easier for n00bs. But man, Brawl is still pretty hard. See, most people played SSB, and SSBM, and have already mastered the basic/advanced technique of the series. So learning to play Brawl was no problem. We jumped right in, and proceded to smash our way to victory. But see.... I noticed this with Nintendo, in general. They aren't making their games appeal to the "hardcore" gamers, such as myself, rather, they are making their games "easier" and more appealing to "casual" gamers, so that it's not "too hard". I mean, us hardcore gamers have stuck by them since the start. I don't know why they are not making any competitive games anymore. (The last being Twlight Princess and Brawl, I guess) but see, the point I'm trying to make is, Smash Bros veterans, are turning to Melee, rather than Brawl, because of all the advanced techniques and fast-action gameplay that they took out in Brawl. Sure, they still play it, but to them, it's easier, and less appealing... personally, I love both, and I am very good at both. But there's always going to be arguments and debates about these two games conflicting with each other...
But yeah, wish they had made it so that the gameplay was basically the same. =P