Descriptivism versus Prescriptivism

So the "are hot dogs sandwiches" thing came out at work today and I was amused to watch one of the people who had never heard of it get drawn in, while I and the person who'd never heard of it watched. He had apparently not even known this was a thing, and was quite befuddled by it all. (I was like "Yes, this is a thing, and also a thing about is a pizza a something or other; yes, it is ridiculous; no, you don't need to participate.")

I have never liked these arguments, in large part because I don't like spending time having meaningless discussions, but I've also realized something else that bothers me about it: it's a prescriptivist approach to language. You can sit down and try to work out the definition of a sandwich in great detail all you like, but the fact is most people have a specific image category in their head when the word "sandwich" is said, and it's going to be very similar from person to person-- the fact that everyone has enough common ground to have this argument in a meaningful fashion is itself proof of that.

And trying to redefine it based on elaborate criteria is prescriptivist. So not only are you having a ridiculous argument that doesn't really matter, you're actively supporting a way of looking at language that is wrong and is wrong in ways that do matter, and therefore contributing to the degradation of very important linguistic norms.