I don’t know that it’s always been that way.

I dunno if publishers have been doing this very long or not, but I feel like fans have been using this kind of shorthand for a while; look at any “What system for [X]?” RPG.net thread.

I also feel like some “you can play”s are bigger flags than others. The AGoT comparison is one of the most problematic, IMO, as it’s just as ill-defined as when someone says “gritty fantasy” — SCUP may be the one game that actually knows what it means.

And remember that what a lot of people want out of an RPG is emulation, so telling them what media property they can revel in proves helpful.

(Granted, I also find it kind of weird, because honestly I’d argue you can “play X” with virtually any RPG, depending on what your expectations are.)