I certainly agree with the OP. The only venues to make money in the gambling industry are sportsbetting, poker and I would add blackjack, yet I don't think counting cards is viable anymore as most of the decks are continuously shuffled.

My question is what income did you have before sustaining yourself solely from gambling?
Also doesn't it bother you that your "job" doesn't add any contribution to the society? I mean you're taking money from the casino and that's it - playing your edge. At least a trader provides liquidity in the markets for the hedgers while a gambler doesn't have much impact unless you do something significant with the profits which is another story I guess.