Gambling site was built by the owner to give him the profit of money he has spent. Gambling isnt a charity foundation that give people free money anytime. Although there are some professional gamblers out there, the site owner surely will be always trying to beat all of them. Thats the fun side of gambling, where we could test our luck and skills combined against the house. Maybe you couldnt win everyday, but if you bet responsibly and patiently, you couldn't be disappointed so bad.
Well gambling is business of course owners will always want their gamblers to lose in the long run because they are going to get profit if their gamblers are going to lose. And I haven't heard someone that he is winning in the long run. Most of the time, gamblers are just losing in the run when they win that is just for a short time.
I heard that some are winning in gambling but that was just a story since I do not know their names, and yes we will lose in the long run and that is base on my experience as well as gambling sites are designed that way.