Just blacklist the bad guys. If players google them and find them widely blacklisted, they will stay away.
Banning the good guys makes no sense to me. It will show everyone that no matter how clean you run your shop, you will get blacklisted anyway. So why bother running a clean shop?
Run responsible affiliate sites and explain to your visitors why you recommend only certain RTGs, and you will make much more of a difference. Players who love the software aren’t going to stop playing it because your site carries no RTG. You do them a much bigger favor by seperating the grain from the chaff for them, that way you look out for their welfare.
IMO that is like prohibition, if you ban something people will find it anyway. You failed them because now they have no guidance to help them pick a decent place. You’re sending them into the world of sleeze.