Why bring religion to gambling at first place ? Let's just see it as a person who is winning money from gambling.
I believe because religion typically teaches that gambling is taboo or unethical to do due to greediness while the subject is a preacher of this teaching which show hypocrisy.
You are right. If it wasn't the prophet and just a normal person then it would have totally depended on the person whether to follow the religion and stop gambling or not but in this case since he's a prophet, it's ethically wrong for a person who teaches others not to gamble and gambles himself.
I don't agree to ban the user directly from gambling but we can restrict a gambler who is always winning money.
After a certain win if the gambler keeps winning then casino owners can impose a restriction on him because that's how they can keep the business running.
Is there any difference between banning to restricting? Both of this action has same effect to gambler since they can’t use the casino anymore to gamble. I believe limiting is the right term if you are pertaining to decreasing the amount of bet which players can put on his bets.
You are right again. The term should be limiting the user from betting so as to reduce his betting amount so that he doesn't make enormous returns.
I am saying this because I have seen this being implemented on a casino site.