I don't play professionally although i have goals of eventually doing so, and I have thought the same thing as you: is this a worthy profession or a lowlife way of making a living off the weakness of others?

I have concluded that there is nothing wrong with it based on the following rationale.

1) I am playing against other consensual adult players.

2) Poker is a competition and people like to risk money to compete. Just because I happen to win in this competition, I shouldn't feel bad about it. If I were to lose, I'd take responsibility for my own actions rather than feel violated by the winners. And lots of money in the economy operates on a similar "feel good to compete" mindset. Consider a pro sports teams. The billions generated by pro sports comes from people who get a thrill out of the competition, even if it is just vicariously through their favorite team. Is the $60 the NFL team charges at the gate any more or less moral than the $60 a poker tournament costs? What about other entertainment venues? If a person loses $100 playing cards, is this less moral than $100 on videos, concerts, or other activities?

3) I can't feel guilty if there's a small percentage out of control addicted to gambling. Just like a beer company shouldn't feel guilty if not everyone can control alcohol responsibly.

4) If Joe Schmo decides to open a business and gets creamed by the competition and his wife and kids are left out to dry, we say that's the perils of doind business. If Joe Schmo decides to play poker and loses, that's the perils of playing poker. Every economic pursuit has risks and tough competition, so a guy can go bust as easily opening a restaurant as he can trying to be a poker pro.

That's about my line of thinking for what its worth.