It takes me about sixty seconds to flip through the monthly flyer from the laughably named "Science Fiction Book Club" and I don't think I've bought ten books from them in the last three years.
By the time I've crossed out all the sword and sorcery crap, all the vampire and zombie crap, all the TV and movie spinoffs, all the $30 comic books, oops, "graphic novels", and all the reprints of SF from decades ago, there are usually less than five new SF books a month to choose from.
I see exactly the same thing in my library and in bookstores. For the love of Pete, can't we separate out all the fantasy/gothic stuff so SF readers can more easily find what we want to find?