Because the game is obviously console-centric, and very few games let you label your saves on the console (this is to say, that, to their biggest audience, it's not expected of them, so why bother?, not to bash consoles in general). Why they couldn't have added that to any of the versions to alleviate the multiple character headache is beyond me.
Yeah, the console port is very prevalent and I thought of this regarding the many in which the game saves. Oblivion, Fallout 3, and New Vegas save in identical manners. But didn't Mass Effect and Dragon Age save their games to their respective characters? Like you would have to first select what character you wanted to play before loading up a game?
I just can't help but feel that surely some developer or playtester said, "Hey, I think there might be a better way of doing this..." and in response that person received "Whatever reason why? This is the way we've always done it. It serves its purpose, now get back to work on designing such a wonderful UI!"