>>528600837
I think you listed the reason for it already. There were only the few maps for it, and there already established zombie mode servers with players that have a hard time giving ZI much of a chance when they already had their own variation they liked. Couple that with the fact community servers in general are already lacking in snagging new players, and you can see all the things stacked against it.

Which is especially tragic because I do not at all understand how people can find ZE or Engie v Zombie Medics the least bit interesting.