Ah I missed the part about sports betting. There are degrees on "badness" when it comes to gambling. I think that sports betting may be less bad than a casino (although I could wrong about that). A poker game with your friends where the most you lose is 5 bucks is definitely better than both.
As to the addictiveness, I don't know that it's that much worse than other hobbies. My parents, for instance, keep buying vehicles they don't need, but they would never lose a hundred grand gambling.
It depends on how negatively its affecting the person's life and how many people tend to get addicted to it. I know there's whole sectors of counseling and mental health dedicated to gambling addiction. Also, a gambling addiction can be life wrecking. Your parents are probably not using their money in the most wise manner, but the car purchases not destroying their relationships (I hope!).
High time preference people will make financial decisions that low time preference people think are wasteful, but the specifics of their spending just have to do with their consumer preferences.
This is absolutely correct. What I'm trying to get across is that while you can overdo anything, but gambling has a tendency to be come a problem much easier than other things.