It’s not that it’s dark, or negative vs positive. As humans we’re strongly attuned to the subtleties of human faces. When an AI image is a bit off on a piece of architecture we won’t notice, but when it’s off on a face it looks creepy and wrong.
There are lots of beautiful AI images out there, but they don’t have faces in them; they’re scenic or architectural or design-oriented (someone in Midjourney has been making a whole lot of textures, perhaps for a game?). On that scale the AI quirks can look charming & artistic.
It’s easy to ask for pretty pictures. Me, I like really fucked up things, so I guide the AI in that direction. It’s just a matter of taste.