Daniel Bryan most certainly does have a personality, he just hasn't had the chance to let it shine lately due to the fact that guys like Miz, Orton, CM Punk, and Cena are eating up all the time for promos. In case you don't remember, DBD has been a part of a few segments where he allows his personality to shine through. It's a combination of humble intellectual plus confident competitor, which was evident in his backstage exchange with Edge.
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Also, this thing with the Bellas has allowed us to more of his personality, a sheepish, "go with the flow" type of guy.
Furthermore, why use a recycled gimmick on a wrestler with the potential to be a great draw for the WWE like Daniel Bryan? He's clearly talented enough to come up with his own personality/gimmick, let him blaze his own trail. And why would they want to bring up the bad memories of Chris Benoit? The WWE does everything in their power to erase him from the history books, giving him a gimmick like "The Angry Mongoose" would a clear allusion to Benoit.
I think the WWE should give DBD more time to develop himself as a character before they start assigning him a gimmick. He's a talented performer in all aspects of the business and he'd be more interesting if he creates his own destiny.