It works the other way around. Facebook is retarding their growth right now, when they can't afford to have it retarded. On the other hand, when they are big, they can afford to make users jump through hoops (and identify themselves).
That's really not true - Facebook, when used properly, can be an astoundingly good driver of growth. If you're not the type who would use Facebook, you're probably not the type of person who will drive their growth anyway, so why should they take away time from optimizing for those users who will?
