I think it's possible nowadays to earning a living just with bitcoins, but that's need real investment and good budget to start with
Nowadays you can easily exchange your bitcoins into fiat and consume it for earning your living
It all depends on where you live and what standard of livings you got.
Personnally I nearly live only on my btc revenues

Very true. For people who live in places around the world where the standard of living is 2.00/day then they could certainly be living off of btc - even faucets and signature campaigns could sustain them and more.