Yes, you *can* make a living. Whatever you choose to do -- backgammon, poker, golf, dart, basketball, bonds trading, or playing the sackpipes -- if you are among the best of the best you can *always* make a career of it.

Personally, I'm an intermediate player, haven't played for very long but at least I've done my homework and I'm playing fairly tight and low limit. So far I'm happy to break even. However, even if I turn out to win consistently over, say, the next half year, I would not want to quit my job and turn it into a career, for the following reasons:

1) With poker as a single source of income, I would be very vulnerable to the occasional draughts in income. If the rent is at stake, maybe that would impair my judgement. In any case, I would need a very large bankroll to hedge myself.
2) There is not always a correct answer in poker. How would I know for absolutely sure that I haven't just been lucky for a while?
3) It's a lonely job.
4) Not the noblest of reasons -- but it's easier to hide any poker incomes from our local I.R.S. if I have a real source of income. I live in a country where we pay aboub 50 (yessir, fifty!) percent in income tax

Also, I do have a decent job (software developer). I actually make good money, get good food and a certain prestige from it. There are good days and bad days but all in all I'd probably miss it.