S.T.A.L.K.E.R. is popular in certain circles and it is very popular in russia so I don't see them stopping production of the franchise anytime soon if that is what you are worried about.
I also don't believe people should think that "There can only be one good Post-Apocalyptic Survival game" Because:
A) Both the Fallout series and the S.T.A.L.K.E.R. series have something to offer to the genre as a whole and both play to different atmospheres and tones (I have played many hours playing both and loved both of them).
B) S.T.A.L.K.E.R. is not post-apocalyptic, the zone is contained inside the post-soviet states.
I also don't believe people should think that "There can only be one good Post-Apocalyptic Survival game" Because:
A) Both the Fallout series and the S.T.A.L.K.E.R. series have something to offer to the genre as a whole and both play to different atmospheres and tones (I have played many hours playing both and loved both of them).
B) S.T.A.L.K.E.R. is not post-apocalyptic, the zone is contained inside the post-soviet states.