It's highly-regulated in favor of the house. These gambling concerns are criminal-adjacent corporations with political connections and weak campaign finance laws.
Edit: Clearly you don't misunderstand that, so what's the complaint?
Gambling has a very strange effect on the human psyche. I never hear anybody come back from Disney World bragging about how much they won. But I've met tons of people who "always win in Vegas". I know a few people who seem addicted to Disneyland. I never understood it. Season passes every year. Maybe one visit a month. Even when they don't have children. It seems weird to me. But the effects of gambling on people's brains is even more weird.
It is only criminally-adjacent in places that perceive a giant risk to people and so have made it illegal. Otherwise, it is as criminally-adjacent as any source of wealth or power that has an incentive to build barriers to entry and to stifle competition.
But the claim seemed to me to be about the present day. Today, I think the industry falls about the same place as big-oil or big-pharma or big-auto or big-politics. That is, plenty of people would call them all criminal-adjacent. But it still makes me wince a little. I'm sympathetic to them all being heckled, though.
Could it be a way to launder money? Jimmy "No Nose" comes in with $40k cash every weekend and loses it gambling, and "nobody knows" where a guy like Jimmy gets that cash so regularly.
[1] https://www.gamblingcommission.gov.uk/print/The-money-launde...
[2] https://moneysmartathlete.com/betting-industry/money-launder...
If you like spending all your dime on drugs, dice and so forth then fine, but let's not pretend the guys selling it are fine upstanding businessmen.
'Criminally adjacent' means literally, adjacent to organised crime.
This is not the same thing as 'above bar businesses are 'adjacent' to anything that is not' , or 'aggressive competitive measures'.