If you are a poker pro, you can easily live with bitcoin poker.
a trader? Ok, you can trade alt and btc daily for money.
a gambler? Yeah you can earn money from gambling.
So Earning a living with bitcoin is very possible.
you can't depend on gambling as being the money for your daily needs and stuff. no matter how pro you are at poker, you'll eventually end up being in the losing side. trading is the only option that makes sense to live from your profits if you have a large enough balance for investment purposes.
Yup gambling is totally waste of money, trading is a good way to make profits on regular basis and if you have good capital to invest at initial stage then it will be an added advantage.