> People like to play Blackjack because they know it can be beaten.
No, people like to play blackjack because they *think* it can be beaten. Whether they're right or wrong about this has little impact on their desire to play.
> Whether they actually will beat the house is another matter entirely
Exactly. It doesn't matter if they *can* win. Frankly it's better if they can't. What matters is that they *think* they can win. Casinos love optimists.
> Having enormous, permanently shuffling decks
> completely blows that illusion away.
Only if you have any understanding at all of probability. Granted, we're talking here about extremely elementary prob and stats, but the target demographic for casinos consists of people who think balancing a household checkbook is hard and know even less about probability than they know about finances.
Such people see a shuffling machine and if anything probably think it makes the game more fair, on the theory that a machine would shuffle more randomly, and thus more fairly, than a human. A human can stack the deck, but a machine would be fair, right?
People who know any *math* understand that randomness favors the casino because the odds are stacked that direction. But gamblers don't know that, and even if they're *told* they don't really believe it, because it's counterintuitive if you don't know any math. (If they *did* understand how the odds are stacked, they wouldn't want to gamble. Math geeks don't play casino games.)
> I can see it turning more people away than bringing them in.
People who are turned away by not being able to win don't go to casinos in the first place -- well, not to gamble against the house at any rate.