There's a rule that's popular which is only gamble only what you can afford to use, and credit card could be a good weapon to break that simple rule.
I am not saying everyone who gambles with credit card is bad, because I know credit card is also good for convenience but people who are prone to addiction might use their cc for gambling negatively.
That may be somewhat true but a credit card really in most cases is a relief.Whenever we run out of money we use that as a mean to buy goods and pay the debt every month to the bank.The fact that may impact someone in a negative way is not a convincing argument that this should be banned.In Europe most of the gamblers gamble exactly with that payment method and maybe other countries follow UK making difficult for many people to gamble.