Gamblers are having fun and most of them are making a profit, even if there is a house edge, the house edge is very important so casinos will not go out of business, this is their guaranty that they will stay to serve gamblers it's a necessary evil but gamblers are ok with it because they can still win while having fun.
If you really see it that way you should read again why there is a House Edge and what effects it has 
Because of the House Edge, a player cannot be profitable in the long run, let alone "most of them". If this were the case, the House Edge would not work and the casino would go bankrupt in no time:
