When you are suggesting a gambler to go for it only aiming for fun, probably he will quit after some time because they do not accept the fact of gambling like gambling for fun. Maybe people are having alternate resources for having fun and entertainment what they need and they are coming into gambling only for making good profit that too in an easy way.
Yes, if people are gambling for fun then they will stick with very least bet amount or they will gamble only for free like with faucet money. Then the survival of gambling houses will be very challenging.
That is the reason some gamblers are making good profit and they are promoting themselves as the winner in gambling and making others to follow him to gamble for making profits.