Well I think it's pretty established that WWE has no idea how to build faces.
They just try to get people over as heels, and then once those heels become "cool" enough that they stop getting heat and start getting popular, they turn them face.
Looking at the current roster, that's how Cena turned face, that's how Orton turned face, that's how Punk turned face, and that's pretty much how Sheamus turned face, and those are the top 4 faces in the company right now.
Beyond them, the best way to be a top-level face is to just be a long-time veteran who'll get cheered just for being recognizable (Triple H, Big Show), or to be Rey Mysterio. And then beyond them, you have Zack Ryder who WWE had positioned as a heel a year ago who got his own damn self over as a face because WWE has no idea how to do that.
So I will agree that turning Bryan heel is kinda dumb and counter-intuitive, but given how this creative team operates, it's probably the only way he'll ever get to main event face status in their eyes--by serving his time as a main-event heel until he gets more popular than other heels and forces them to turn him back, like Truth is doing now.
--
Thank you, Eddie Guerrero.
http://bryandanielson.net/wp-content/uploads/2011/12/photo3.jpg