The Real Name Fallacy
Thing is, if I had to guess, I would say Facebook doesn't attempt to make you use your real name to make the community better in the first place. That's almost certainly just its pretext for everyone who's willing to fall for it. Most likely, it does that to make sure it can identify you globally and uniquely for commercial/advertising purposes. Think about how much more valuable your online identity is if you go solely by Jon Doe rather than by foolover123, bar456fudger, and nighthowler789?