I love Space Opera genre with light humor, fast space ships and aliens. Actually, that's my preferred genre to write in, because you don't have to deal with old boys who hate warrior-women in fantasy, but I don't, because it is an extremely hard sell.
There are studies that indicate that the reader engagement is significantly lower with a work of sci-fi, because of all the unfamiliar words and images. It is probably a bit easier for the artists because you can conceptualize the looks of new creatures and landscapes, but when writing, it is far harder to lead the reader through visualization so that it is not boring to read.
Unsurprisingly, the two subgenres that lead the way in sci-fi are the android romances and dystopian sagas, since they don't have to plow the unfamiliar so much.
Sometimes I do really want to write a sequel to my space opera, but the thought of nobody reading it... meh.