I'll speak my very personal opinion, so, first of all... just Poker has technical part, which is "the" difference between other games... the habilities is far away from the concept of been just a "luck" game. I saw many people, and I said Many, Pokerstars has thousands of stories about winners and carreer on poker. I made a decent bankroll there but I don't play anymore (just because of time)... so that's it, this is a question of study, dedication and lotta psychologic work.
I can't deny that gambling can be a profession in a hard way. And every time I watch poker tournaments I'm thinking what if I'm the one sitting there.
Millions of dollar are being involved for each players but I guess those people who are making it profitable that way are already rich.
So for those aspiring professional gamblers they need to have bigger bankrolls before they are going to surrender their own life to gambling.