Whenever I get the chance. I have made plenty of money playing pool. I also make sure I play guys that I know can afford to lose. That usually ensures they don't whine after they lose.
Would you mind answering my question now? If the bet is $10,000 and he quits after winning the first set, is he a nit? He bet an awful lot of money didn't he? My point is, if I play a set for $100, I am playing to win $100. After the set I will never feel any obligation, win or lose, to play again. All of the terms were set forth before the set. If you are going to cry if someone quits, make sure you make the game the way you want it before the set, and don't just assume that your opponent knows your "old-school" theory of gambling.