How fan bases can kill something

What is a fanbase?

Basically a fan base is a group of people that are very fond of a certain form of entertainment games, movies,TV show etc

Some aspects are
-they enjoy the thing and anticipate anything related to it
-they make fan art or make there on OC's on it
- they buy it every time it comes out for example the COD games

There is nothing bad about these traits in fact I am guilty off every single one of them except for me it's battlefield games as I never got into to COD and don't plan to