[Spivak]

I think there's a "the world is entirely grey" presumption here that prevents the full analysis. You're not treating "it depends" as the fully-fledged position that it is. If you did you would see that there are now three positions the originals X, Y, and a new one Z that are incompatible. They can't all be right. X and Y have lots of supporters, why do you presume your new position Z to be correct simply because it lies on one of many possible lines to draw between X and Y?

Surely for any real world issue the positions X and Y were the result of someone else's seeing the nuance but landed in a different place than you did.