That is a nature of casinos, to win in the long run, tho, there might be some that loss due to some good gamblers.
There are not many gamblers who can beat the house, they are just lucky that they hit the jackpot, but it's good that there are who hit the jackpot, because it will make people motivated to play, I have seen people actually winning huge jackpot, so people do not have issue at all if the house an edge as long as it's provably fair and the winners are getting their money.