It can be profitable in the long-term if:
1) You play poker and other card games where you play against others.
2) You are an expert in horse races.
3) You are an expert in some other sports, use crossbetting and find betting sites that dont ban you when they realize you are a winner.
4) If you find errors in physical casino games. Like the roulette not being 100% completely flat and some numbers tending to appear more than others in the long term.
1) I don't look at poker as a luck game, rather skill game(88% skill over luck)
2) I never heard of such gambler.
3) Only profitable betting is arbitrage, but there is risk that you will be caught and site will ban you and take your money.
4) Now, that is against every casino rules. If you do that casino will probably close your account and take all your funds.
And this with roulette is nonsense. I can assure you game is 100% based on luck. There is no pattern.