There seems to me more women readers, young women so that relationships are figuring more in them, but they certainly aren't romances. Whereas a romance set in a science fiction setting is a romance first, not a book with romance in it. That what mine have been. The focus is on the relationship. In science fiction it's focused on the culture and the politics and the ideals of it and the characters, not necessarily the emotion.
Romances are emotional.
I think it's probably more sensible as a writer to start with something that's more accepted and has a bigger audience. I think it's because I read historicals. I don't really like contemporary and there really weren't the futuristics at the time when I started writing. I didn't even know they existed until after I started writing. They don't have a very big audience, but I like doing them anyway.