Can somebody explain the problem with allowing people to choose their own names? They claim it is to foster "an environment." What kind of environment? Surely n

Can somebody explain the problem with allowing people to choose their own names? They claim it is to foster "an environment." What kind of environment? Surely not an honest one, since using real names doesn't cause people to act honestly. Forcing real names fosters an environment of rigidity and conformity. But I guess people like that about FB and Google+. At least MySpace allowed you to pick your colors. The Internet could be it's own place, it's own unique environment, but instead people like FB or Google+ want some poor attempt at a one-to-one mapping of the real world.