What matters to publishers is whether an author has built up a strong enough brand and social media presence to make selling their book a no-brainer. If you have enough people following you on Twitter, you could sell word soup to a major publisher.
Until the publication of my first novel, I'd never consciously thought about the importance of cover design. But the graphic artist's crucial role in the novel's production (and possible success) became apparent. The artist's talent was vitally important to the commercial viability of the novel.
I hate when there's an elephant in the room. And let's face it -- we've got quite a few elephants roaming around the online community. One of them is the fact that everybody's trying to pitch everything, yet nobody knows HOW to pitch anything.