I feel like it’s been going on for a long time: at some points, it even went circular (when I was in grade school, someone thought the selling point of DnD was that you could even play Dragonlance with it). DnD always had a certain “it does Tolkien” to it; Vampire had a “it does Anne Rice” pitch.

That said, I’m in your camp these days. I don’t just not-care about others properties; I mostly don’t even want other people’s settings. Looking at the pitch for 7th Sea, I lost interest at the prospect of spending so much effort looking over the details of someone else’s imagination. That’s what I and my group are for!

These days, BitD is pretty much the outside border of what I’m interested in in terms of someone else’s imaginings.