I understand why you're worried about that. Allow me to share something about myself in the hopes that you might gain some insight into your own life.
I also believe that the games I want to make are not typical of the blockbuster stuff - but that's because I think most blockbuster games suck and fail to bring people together, which should be the goal, IMO. I'm most concerned about making a game that opens people's minds or enriches the interaction between friends, instead of isolating them. If I can do that, it could be dressed up like Modern Warfare 2 for all I care and I would still be happy. And I think it'd sell well. Maybe try focusing on what you DO have in common with others than what you don't. I think the most important thing to know about life is that happiness comes from other people (imo), and that's true for everyone. I think Nintendo shares my belief about what video games should do. And even though they haven't done it exactly right, the success of New Super Mario Bros Wii is an example of how much people will like your game if it really lets them have fun with their friends. (Also, good marketing. The title is probably the best thing about it. Wii owners don't know anything about games, of course they're going to buy the new super mario bros game! That was their favorite game when they were a kid! Har har)
Don't get me wrong - I want to make a game that is so awesomely sci-fi and fantasy and philosophical that most people would say WTF, but I think you can give up the sci-fi and fantasy and keep the philosophy - subtley - and make a very popular game that reminds people to be ethical, or whatever.
However, finding the opportunity to make a big game is daunting. There are SOOOOO MAAANNYYYY people trying to become game developers. In ten years, when there are like fifty million little developers, how will one game be able to capture the attention of everyone? I don't know.