Maybe it's because of pay-at-the-pump popularity now but have you never seen someone standing off to the side of the main gas station counter surrounded by a pile of scratch offs? People exist who will drop their entire paycheck on them in a single day. I've also seen people buy irresponsibly large stacks of Powerball tickets and not just the "oh, I like to fantasize about winning so I buy a ticket each week since you can't win if you don't play". It's gambling all the same.
Regulating it also removes demand for underground or foreign online gambling.
For these private betting firms, it's open season trying to find whales like mobile gaming, and there's no end to their greed and exploitation.