Gambling addiction is a brutal public health problem. As I understand it, gambling addicts have a very high incidence of suicidal ideation. When people work in these industries, their paychecks are directly coming from putting people into deep suffering.
That's a matter of opinion. There are those of us that believe that it is a gross violation of one's human rights to dictate how they're allowed to spend the money that they earned.
It's a side effect of liberty that people can choose to put themselves into deep suffering. I know people who do the same by blowing all of their money on designer clothes or expensive cars. Nobody is talking about regulating poor people wasting money on those things.
If you earn the money, you're entitled to piss it away. Them's the breaks.