Gamblers will always find a way how to bet on their sports. This is just one way to limit their credit card usage. Maybe, the government is also receiving complaints from these credit card providers so they take action where they have control over with. But I do agree that these regular gamblers, they can go beyond their means if they need to just to gamble.
I doubt that the credit card providers are going to complain to the governments because some holders are not paying or can't pay. It's not a lost for them, banks are big, it won't put a dent on their business, on the contrary it's a win-win for them. The only reason why governments are going this far is that they want to control gamblers, or at least not to get them addicted but I don't think it will work in the long run as gamblers will always go and beyond and find another way to continue playing with cold cash.
For other side of things then they might really oppose but this one would turn out to be beneficial on completely stopping gamblers on making unnecessary spendings which do end up for them not to repay
on what they have used.
Also, if banks would oppose or trying to appeal then is there something that they could do once government do make the voice?