Could be in any context. I do it a little on UFC fights but that’s a relatively low amount and I can afford I to lose any time I do. It seems like it’s becoming a really wide spread problem though, at least in the US. At the same time I don’t see why it should be illegal. Granted I also don’t think any drug should be illegal.
I think you’re misunderstanding my point. You’re completely right that the house sets the odds it it’s own favour in order to make money, I’m not arguing against that.
My point is that setting odds in casino games like roulette is trivial, and there are no confounding elements that can suddenly make your odds wrong. In sports betting, setting the odds is highly non-trivial and pretty much impossible to do exactly. The better can look at the odds and consider whether they think the house has under-valued a certain game, which is possible, and bet on that. If the better is more well informed than the house, it’s actually possible that they make a net win. That’s completely different from a casino game, where the odds will never be in your favour.
I would argue that sports betting is a fair game, in the sense that the house sets odds, and you can consider whether those odds are in your favour or the house’s favour. Obviously, they will try to always set them in their own favour, but (also obviously) they can make mistakes that are exploitable to a well informed better.