I'm afraid I can't follow. How does it go against roleplaying if you know and have decided on your character's background? So basically you want to make up your own background, and not be limited by the choices given by the developers? Ok, I can see some merit in that. But I have to say, I don't think broad backgrounds limit your chance to make up most of the background of your character.
Examples of what backgrounds I would like to see:
"Raised by a soldier": +1 STR, bonus to swords, polearms and thrown weapons
"Alchemist's apprentice": +1 INT, bonus to alchemy
I think these do not limit your roleplaying in any way, but contribute to it. You may still be an intellectual, or a lithe person, who was raised by a soldier. You may have worked as a lumberjack, a goldsmith or a carpenter. You may have been an alchemist's apprentice, but you're still a lump of a man and he simply couldn't find anyone else.
I agree that those kind of backgrounds wouldn't limit you very much, sometimes limitations can even make you more creative. Still, given the choice, I would prefer total control of my character's background and personality instead of almost complete control. As far as I'm concerned my character's background need only exist in my imagination and will manifest itself in the game by the moral choices it leads him/her to make.
Both ways has their merits, it's just a matter of personal taste.