Lots of great comments here - I especially love hearing you guys' stories.
A lot of you didn't read the post I wrote, but to reiterate, I'm not talking about running cons, cheating, or sharking. I defined "hustling" as playing for stakes, so call it "stake playing" if the word "hustling" has too many negative connotations for you.
What I'm proposing would eliminate many of the things that those of you who are anti-hustling dislike about hustling: I propose clear rules, clearly-marked "cash" tables, a referee, etc. Of course there is nuance, and the details would need to be worked out to accomplish the general aim, but the point would be to eliminate the negatives, and keep the positives. A system could be devised for how to offer to spot balls, ask for balls to be spotted, etc. - I'd suggest writing everything like that down on a chalkboard.
As far as the gambling component, opposed to putting money on oneself, people already gamble on everything, and 99% of people who gamble on pull-tabs, lottery, etc. come out behind. Betting on the outcome of billiards games would be more interesting, and give better odds.
For fish like me, it would be like stepping up to a carnival booth and spending money to try to win a stuffed animal. I'd most probably lose, but it would be fun to play a skilled player who I know is actually trying to win, and maybe I'd get lucky. Meanwhile when the big dogs were playing one another, I'd have a chance to watch how these guys play when stakes are on the line, and wouldn't be the one weirdo watching their game.
To be clear, I'm not talking about making hustling ubiquitous in every bowling alley and bar - I'm talking about setting up specific places where playing for stakes would be done out in the open, and would be well-regulated to eliminate fights, robbery, cons, cheating, etc.