One of the main problems with a purely descriptive account of laws is that it renders those laws epistemic. In and of itself, this is not a bad thing. Certainly, our expressions of laws (whether or not there is an underpinning metaphysical reality to them) are entirely epistemic. When I say, "Gravity is a result of the curving of space-time by mass," I am expressing an idea, an epistemic state.

I agree that saying something "Is a Law" can be used as a curiosity-stopper, just as you suggest. Particularly when the speaker is talking with someone outside of their field. I also agree that conceptions of natural laws where physics is necessary and biology, chemistry, etc. are unnecessary leads to a problematic ontological barrier while trying to claim that physics, biology, chemistry, etc. are "out in the ether" leads only back to the difficulties of Plato.

But the epistemic state claims to be about something in the world outside of my head, and that's where things get a little tricky. When we ask why there is a regularity that we agree on epistemically, we ask why there is a regularity and not something else. Just saying that the regularities are necessary seems as much a curiosity-stopper as saying that "It is a Law" as is saying that we can't know why there is a regularity. Equally bad answers to this include but are not limited to "We only care about the epistemic state" and "There is no fact of the matter about what makes a regularity a law." (Which are sadly not straw-men, but actual positions held.)

So saying that laws are epistemic rather than metaphysical doesn't get rid of the mysteriousness, it just changes the curiosity stopper from being about how laws are implemented to how they exist in the first place.