Of course it is casinos. The idea of house always win simply proves that most of the gamblers are losing often than with winning. Gamblers are just up with quantity but if it is profit then a casino will be more advantageous; transaction fees, losses, and the likes. However, if you're  gambler you won't percieved it as gamblers vs other gamblers but rather, gamblers vs the casino itself. Casinos are most of the time winning over those who are losing and that's just how a business work; citing the demand and targetting it for gains. As long as there are gamblers who are winning, then others despite of loss, will continue playing for the sake of getting the same fortune. As we all know, no matter how hard you desire to win, if you are unlucky then things would either be the same or worse. Minding the gambling site of earning more will just stress you out. You cannot force gambling to be in your side but you may force oneself to be preventive of the outcomes.