"Halo 4: I Get a Woman!" - Sgt. Mjr. A.J. Johnson, RIP

[DarkHalo003]

Or they can ditch backwards compatibility and not bother with spending resources on making emulators which aren't guaranteed to work with every title.
Ditching backwards compatibility would allow said resources to be used on something more useful, like say reliability?

Or they can invest resources to make it work flawlessly (for the most part).