This seems like quite an irrational strategy on the casino's part.

Hmmm. Does it also seem irrational of them to break the leg of someone who borrows a lot of money and can't pay it back? Wouldn't it be more rational for them to break legs of random drunks who are less likely to recognize their assailants?

I hope my flip response doesn't seem too hostile. Of course the casinos that cheated me weren't doing it to make a few extra bucks. They were doing it to punish me. Of course, for blackjack card counters, simply banning the player is also a viable strategy. And it happened to me in more than one casino. But banning doesn't work so well with online malefactors.