I get asked by lots of people, not so much for advice, but to confirm what they already believe to be true. Let me tell you this.
People can learn.
Publishers don't understand that covers are part of packaging which is part of marketing. What they fail to realize is that they WILL sell a book by its cover. And they get something with clip art on a pink and green background as a cover and an inside looking like a college freshman's first term paper. And they wonder why their books are rejected by every buyer of every wholesaler, distributor, and retailer on the planet. Dumb, dumb, dumb.