Someone asked me recently "why scifi?"
Why do I write in the sci-fi/fantasy genre?
Science Fiction/Fantasy is interesting, and more fun to write. With things like mutants, parallel worlds, and space travel acceptable, there's a million possible stories that can be written.
Why not some realistic fiction?
Well, there's two reasons for that. The first is that the majority of real life is boring, dull, and monotonously mundane. The second is that my real life is pretty rough and I'm afraid I'll end up having an emo fest in a book. The reason I started writing was because I wanted to imagine things differently, not write about how they are with my life.
You've always wanted to write some historical fiction, why don't you do that?
This is simple: research. In sci-fi you can get away with pretending that engines can run on butter or something in the future, the facts don't all have to be, well, factual. I definately love looking up some things (like say, spiders or dictators), but I don't like looking up everything to make it work in with history. Why do you think The Conqueror takes place on a fictional island?
Besides, I love reading Sci-Fi/Fantasy and I know I say this all the time, but "the true key to being a good writer is being a good reader."