IDK GalCiv is pretty well known, Ive yet to see a less then 9.0 review. Also just about everyone in my union uses GalCiv as the "Bar" for other TBS, like "Is it as good as Galciv2?"
The
entire TBS genre is very much a "niche" genre... it just doesn't have enough people "behind" it to make it a truly major genre, unfortunately.
I really dont think one genre has more of a mainstream appeal then another...
Let me try to make this simpler: when is the last time you heard of a TBS getting the kind of buzz SC, C&C, Crysis, Doom, Quake, Half-Life, etc etc generate... and they generate it
effortlessly. (Well, relatively effortlessly anyway)