Hate the be the party pooper here, but here goes...
Gambling, its commonly associated substance addictions, and the fact that it is illegal, obviously didn't work for pool. In my opinion it pretty much killed it in the US. The consequences of gambling, and any other addiction, are nowhere near as trivial as you convey. The people who can live with a long term "successful" quality of life (however you measure that) and participate in gambling are the rare exception rather than the rule. It turns people into total and complete losers in life. Good luck having health insurance, a retirement worth living, raising a family and putting the kids through college with a gambling habit. I see it happen in my local rooms more often than not, guys out gambling away their family's money for that rush. The guys that gamble the most often happen to be meth dealers on the side. I won't let these people in my home.
So yeah, I would be perfectly happy for gambling in all of its forms to just disappear from American pool rooms. Maybe 1 in 10,000 can handle it responsibly. Until it does disappear good luck getting soccer moms feeling comfortable sending their kids to a poolroom for instruction. It is time for pool to evolve here.
And yes, years ago it was not unheard of for pool rooms to get raided by law enforcement when they actually decided to enforce the laws for some reason. If you somehow get financially successful at illegal gambling (one of the exceptions), the tax authorities may just catch up to you. Best to stick to legal gambling, like the stock market.