Why have names for player characters? Seriously, what is the point? Why not call them Shadowrunner 1, 2, and 3? I consider that about equal to not having a really basic background story. All I'm talking about is a couple of simple lines. "I'm from the Barrens and I used to steal cars while in a minor gang." "I'm former UCAS army and fought in the Desert Wars." I literally made those two backgrounds up in 5 seconds a piece, and typed them in 10 seconds or less.
I rarely run into a player not willing to do this, and it was players that have done this before just being lazy in that particular game. At which point I questioned them. I've never once ran into a person belligerent enough to not answer a few simple questions. And if I did, I doubt I'd continue playing with them. It just seems like someone refusing such a simple ten second request is just a belligerent person and probaly going to be a pain in the ass to deal with on a regular basis.
Deeper backgrounds are excellent, but it's cake and I don't require it. It just lets me build more tailored and customized games for players. I pretty much set the upper limit at 5 pages, and I believe I'm more tolerant than most GMs, since I am a heavy reader. It's the Internet age and many just won't even read a page of background.
I've had some great characters start from very vague concepts as well. But some have started as more detailed backgrounds. Both methods can work. But I think it makes it difficult to go anywhere with a role when you start a game with absolutely have zero to go on. Your character wasn't hatched in the bar where the Johnson is.
Laslty, my games are pretty violent. Enforcing a very barebones background is a completely separate thing from if a game is Pink Mohawk or whatever. To me, it's like a name and physical description. If I don't know vagely what you look like, your name, and where you're from, you're just a set of numbers. Would it be unfair of me to ask someone if their character is thin, fat, or muscular?