Isn't it ironic how we need to time and again protect most people from themselves. And most often it ends in a hypocritical and cynical discussion because the state permits alcohol consumption and smoking and legalized gambling, all pursuits that wash ample tax dollars into government coffers while other vices and pursuits are strictly illegal. It will always result in a dishonest settlement of sorts. Lottery is legal but lawmakers have an issue with little John blowing his 500 dollar account. I don't think any limitation on the demand side makes sense. Regulations should always target the supply side and weed out black sheep.
It's because they don't get part of the loot. This is also why US regulators were so against online gambling on websites outside of US - they wanted their cut. And this is why local gambling is legal and even encouraged.
There's a huge number of people who have lost their life savings in casinos but everyone accepts it with "well, that's how it goes".