This is a good idea in theory. The problem come when you have a 13 yr old posting that he is something he's not, then it's a waste of time. This is what your profile is for, to tell people about you. Even though you don't have a dedicated section for people’s bios, you can sometimes tell the people who know what they are talking about. Some things can't be faked and some information you can't get off the web, it only comes from years of training. The guys that are all talk come out in the wash.
Some may see the bio section as bragging and wouldn't post there for that reason.
Like i said, it's a good idea but i doubt it will happen.