Why won't 343 add in split screen as an update?

Why doesn’t 343 add in split screen as an update even though it is most likely possible, and that there are way more pros than cons about having split screen? Also the fact that people have been complaining about it ever since it was revealed that halo 5 was not going to have split screen, so why wouldn’t they?

The frame rate of the game cannot be changed to accommodate this.

The frame rate and graphics are always lowered in any game when split screen is in use so it can stay stable, so I do not see why 343 cannot just simply do so with Halo 5.

Due to the way Halo 5 has been built, it’s not possible for them to introduce split screen at this stage. You’re welcome to discuss it further here: Official Split-Screen Thread