Because it is a game where the player is bound to lose, they should minimize losses and not think about beating the casino.
Well you are right, undoubtedly I do not know how there are some players who want and seek to beat the casino all the time, the casino does give windows to win, what happens is that those windows of profit or opportunity sometimes one as a player does not take advantage of them and if you are betting repeatedly you win little because you bet little and if you bet a lot then you lose, but it is not because the casino is against us, but unfortunately the randomness including luck at that moment did not work or occur, but there are many players who play hard and win large amounts.
Yup, instead of taking that opportunities to cashout their earning they stay and keeps on pushing for more, being wise especially whenever you have your chance is something that's needed to continue being practice from each sessions that you play the game or you bet with your favorite sports, with that kind of mentality, you'll be able to maximize your win and be able to adds up enjoyment after playing.