The problem with the Korean War is that people know jack-all about it. Honestly, I don't think it was *ever* mentioned in the history courses at my Highschool, back in the 90s, seems like there's very few documentaries about it on the History or Military channels, I don't think there's been a decent movie about it, ever, etc.
It's a fascinating subject (As most wars are, to me), but pretty much everything I know about it has been independent study, in libraries and on the internet and the like. It seems like a forgotten conflict, to most of the nation.
So a Korean War game would appeal to the hardcore war game grognards, if you made it "realistic" enough, but if you were trying for more mass-market appeal, I think it might be lacking.