Exactly. I don't know much about probability but it is said that the slots in physical casinos have their chances set so that every now and then one would give a payout, to encourage those in other slots to continue. Of course it's different with card games but if they want it to be realistic, they'd have to throw in a few "errors" in to make the AI realistic.
If people feel they don't have the slightest chance of winning (though to be fair they really don't have much to begin with), they won't play.
AI can enable companies and enterprises around the world to cut down costs and maximize profits. There have been so many applications and software that help in the business activities and companies like Microsoft, Facebook and the leading firms in the financial sector have been making their millions this way. So it is not possible to make superprofits in the current era without making use of AI.
You have a point. The thing is, with gamblers they prefer to have another person playing in the same table. If the casino put an AI in there instead, it'll be like a noob playing chess on max difficulty - you'd feel very frustrated.
If it is known that an online casino used an AI, that could destroy the players' trust. How sure would they that not all "players" are AI and these are putting an act? After all, it's all virtual, you can't confirm who those are. It'll be like the Truman Show except with AIs.