As far as I am aware of, I've not come across any casino that banned a user for winning too much, some cases i have seen on this issue is where the user is limited to only being able to bet or play some certain games the casino knows that the user does not win that much on, or is not so good in.
Some casinos that try to be a bit fair on the user do still allow the user to play their favorite games or bet on their favorite sports, but they will be limited on the amount of money they can bet on the game.
This is as far as I know, I've never come across someone complaining about being banned for winning too much.
in the case of banning big wins, it's usually because the casino doesn't have a large enough bankroll to pay out big wins to its customers. so that the casino will limit or prohibit gamblers if the winning results are too large at a particular casino.
if you say you have never seen gamblers complaining about wins being banned or limited, look in the fraud section lots of people complain about getting big wins but in the end their funds are confiscated or accounts are frozen for reasons of being detected multi accounts etc.
it is a habit of scam casinos who don't want to pay out big winnings to their customers and use that as an excuse to refuse non-pay.