A video I've recently seen made me quite worried about beloved game series. The video I've seen is Metal Gear Survive Trailer.
Very similar to trailer for Infinite Warfare, this video got huge number of dislikes and negative response, mostly complaining how original author Hideo Kojima, destroyed 29 years of respected franchise and transformed it into a cheap zombie survival.
A thing that Infinite Warfare and MG Survive have in common is they are both in future. In my opinion, this forced "futurization" might be another reason why are people so negatively responsing to them. It changed the core that kept these games for years.