Honestly I can't say how I feel about Brawl competitivly. As a long time Melee player who would not define himself as casual; I'm on the fence.
However, I think more people who are downright forsaking the game aught to have a more open mind.
So, why get rid of wavedashing/L-Canceling etc.? WHY NOT? It's a NEW GAME. It's not a Melee expansion. Now, as cool as a Melee expansion would be, what we have here is Super Smash Brothers in another form. What people really should do is stop comparing it to Melee and just play the game as it is. Now I know that's easier said then done, I too keep thinking "I moving around so slowly" and "It's so much easier to do certain stuff (such as grab edges.)" but you really need to give the game a chance more than just 3 days. Additionally, any game with THIS MUCH HYPE is going to dissapoint you. Weather it's Fox and Falco's Final Smashs being similar, there not being character specific target tests, or big differances from Melee, something is going to tell you that this game isn't perfect in your eyes and you'll be dissapointed. The key is to get over that and enjoy the game.
Now, as for if the game is competitive or not... That's easy. All you have to do is wait for a few months, then, take a player that's new to Super Smash Brothers but has learned how to play Brawl, and pit them against a verteran Melee player. If the game is competitive then the new Brawl player will win because that would show that Brawl has enough Depth for someone to learn tactics and evolve as a player and beat people who don't play the game. In other words, if a game has depth that makes in competitive, wouldn't you say?
In other words, if you really don't think Brawl is competitive then go beat someone who only knows how to Brawl. With your vast knowledge of Super Smash Brothers you should be able to beat a new player despite them having more affinity with the game then you. However, if you can not beat someone who was never big on Melee, then you really have no choice but to concede that Brawl is in fact, competitive.