There are a bunch of studies out there [0][1] (two I found immediately) showing the risks around problem gambling, but like with most vices people who’ve already picked the pro side tend to react in the same predictable ways (myself included):
1) Dismissal: Feigning or having a profound misunderstanding of how statistics work by poking at the methodology like “N=200? That’s meaningless.”
2) Apathy: “So what if some people get addicted? We can’t babysit everyone.”
3) Rationalization: “Yeah but it helps Native American reservations, so...”
4) Downplaying: "Ok problem gambling is bad, but how prevalent is problem gambling really?"
There's also a version of rationalization where people project arguments from the war on drugs to illegal gambling, as though the enforcement of illegal gambling was somehow had costs greater than just letting anyone bet any amount of money from their phones.