It depends on Money that they use for gambling. if the money came from a illegal job etc then that's a dirty money because of addiction on gambling some of people doing illegal just like rubbery,etc for just a small amount of money and they try to gambling it. and it's depend on what gambling their have because There are also many different type of gambling.
Well the topic really stands for religious matter thats why OP asked if this is Dirty or not
But thats true that as long as the money is from good source then theres nothing to think about being dirty
Well, the fact that the profits come from all gambling platforms is not dirty money as long as it is not illegal. Correct, this discussion was really matter on what you had belief on religious because there are gamblers that having a different religious belief. There are religious groups that gambling is evil and there is a religious group ignoring gambling so, let's respect each other belief. If we are gambling to be fair and no one hurts while gambling that is considered clean money.