A book's cover is a strong signal of its content and quality. You absolutely should judge books by their covers. This isn't an accident. Publishers put a lot o

A book's cover is a strong signal of its content and quality. You absolutely should judge books by their covers. This isn't an accident. Publishers put a lot of effort into ensuring covers send accurate signals about the contents of the book. A book with a garbage cover didn't come through the modern publishing process, and it didn't get made by someone who cares enough about their book to put actual effort into the cover. The percentage of books that will be worthwhile with a bad cover is vanishingly small. To a first approximation, it's 0%. It's very reasonable to judge a book by its cover these days. It's an intentional signal; covers aren't chosen at random. If you intend your book to be taken seriously, you need to keep up with modern standards.