Walter Jon Williams Is a Truly Excellent Writer, but…:
According to these highly-qualified professionals, people only respond to things that look like other things that they already like. That’s why, whenever I write a book like Days of Atonement, which was the world’s first (and, so far as I know, only) Gothic Western science fiction police procedural, a book which I fondly assumed might appeal to readers outside the normal SF audience, the publisher made sure to put Death Rays on the cover, to assure genre readers that this was a thing that looked like other things that they already liked, and to make sure that all potential new readers were discouraged from so much as glancing at the book.
Guilty as charged. I see spaceships and skintight spacesuits on pneumatic female cosmonauts, I keep my hands in my pockets. I know it says more about me than about the genre. Just one more reason why books should just come in plain covers.