Because they are looking for every edge or shortcut possible and think they are smarter than the book/casino? They justify in their own minds that most games are "rigged" or the "vig is too high" and think that means they can do whatever? Who knows? The same mentality sometimes creeps into places like SleazyStreet and other scam outfits.
Unfortunately, the 5D casino seems to operate on the same principle and some of their players are smarter than Tony, which isn't saying much. Tony=good linesman, that's all. When you throw a +EV game up in your casino, only an idiot doesn't realize that it's a bot-magnet. If you're lucky like 5D was, you'll get a greedy player who has a horribly scripted bot he probably bought for $20 Web$ that exposes him and nullifies his winnings or a player like Tackleberry you can just simply screw over and SBR will agree with you, but you still get tons of bad PR and look really stupid and not like a place to trust with your money.