Well yeah, but those people are doing that for collecting; even if they want more content out of the game, they are fine with buying it just to have it in their library.
Lately I have decided to play Ocarina of Time: Master Quest. Considering this game was released free alongside pre-orders of The Wind Waker, and besides that, unlockable on Ocarina of Time 3D, most have never felt like they were paying for it; nobody is going to complain about free stuff. I have...