I would certainly find it mysterious and confusing to find a game installed to %APPDATA%, and I've been a PC gamer for over two decades. Saved games and config files, sure, possibly mods too, but if a game installed somewhere without asking first I'd expect it to be in %PROGRAMFILES% or %PROGRAMFILES(X86)%. Either way, as the owner of a PC with multiple SSDs I'd be somewhat miffed by not being asked first where the game should be installed, as I put most of my games on my D: drive, which is much larger (but slower) than my C: drive.

Generally speaking, people don't like being called liars, or idiots.