You're never "forced" to own anything. There's always the option of just skipping it. BOTW single-handedly carried the successful launch of one of the fastest selling systems ever.
A game does not necessarily have to be exclusive to be a killer app. Halo 1 was not exclusive to Xbox for example. If a game is desirable enough that people will buy the hardware it runs on in large numbers just to play it, then it is a killer app.
Wasn't Halo exclusive for years, though?