Just wondering, why no co-op?

Had it been considered but dropped or decided it would be best not to make one?

If it it's ok would it be possible to get a reason as to why there has been no co-op in c3??

-Not enough time?
-Budget?
-Couldn't make it work?
-Manpower? (Not enough people to develop)


Regards,
Jared.


Edit:/ I know that not every game has to have co-op. I honestly love Crysis 3 to pieces but it did cross my mind why there was no co-op..