The original poster seems to be arguing that the gambling industry is doing 'a great job' at self regulating. I believe that statement to be pretty meaningless, and I think regulation is likely a positive thing.

The fact they've done a good job of regulating (assumption) up to this point shouldn't be a consideration when deciding if they should be regulated in the future because we inherently can't trust them, and there is no guarantee whatsoever that it will continue that way (and I believe inevitable that at some point one of them will step over the line if they haven't already)