I'm sorry, but if you don't get why these are two different arguments, there's nothing that I can say that will make it make sense. Sometimes human beings just decide to allow some stuff and not allow other stuff, and that's okay.
Respectfully GB, this is such a horrible answer: "if you dont get [it] " and "Sometimes human beings just decide"
If we cannot succinctly describe the difference, than there is no difference, which is what I believe the point is.
If you really want a succinct explanation, the explanation is that we already know how to regulate gambling. We've been doing it for decades and we know how this works. I don't personally favor returning the law to what it was in 1994 (say), but that's easy to articulate and it's easy to explain how to get there from where we are right now.
By way of contrast, "there is too much sugar in foods these days" is a much more pervasive problem. It's a problem that we don't have any real experience with solving, it's not clear what the solution would even be, and the social costs and benefits of sugar consumption are qualitatively unlike those involved in gambling.
Are there bigger problems in the world than sports betting? Sure. But the existence of those other problems is not a good to reason to shut down discussion of this problem, and that's what this little sidebar is really about. No, we're not going to ban sugar, and we're not bringing back prohibition. That doesn't mean we have to allow everything. It's perfectly fine to say "I think we should allow these vices up this point and no further." That doesn't require that I've sorted all of our risks into some sort of continuum and drew the line in exactly the right spot. Nobody does that.