I don't think there necessarily has to be a big reason behind having an affinity for black ... it's like asking why someone likes burnishing on shoes or whatever. It's just a preference, informed by countless things, consciously or otherwise.
My style is quite severe, so black and grey lend itself well to that severity whereas greys and blues might be lacking in impact. Furthermore, it has practical advantages in that coordination between items is a lot easier, so you can have more complete outfits with less pieces than a more color-coordinated wardrobe might require.
My buddy was telling me about a co-worker he sits next to at work who was OBSESSED with dogs, especially Corgis. He had dog photos, calendars, etc. hanging in his work station, despite having never owned a dog since he'd never lived in a place where pets were allowed.
But the guy recently bought a condo, and could thus fulfill his dream of owning a dog. A few weeks ago, the guy told my buddy he was going to be buying a Corgi that weekend. The following Monday, my friend asked him how the new dog was. The guy looked like he was about to cry. For whatever reason, he just couldn't bring himself to play with the dog. My friend couldn't say for sure, but he's under the impression the guy returned the dog. Not long after, all the pictures and calendars were gone, the dream and obsession seemingly obliterated.
Dogs are fine. People who treat their dogs like actual people creep me out. People who bring their non service dogs into restaurants or other places of business with them are assholes. People who let their dogs sleep on their pillow next to them in bed are gross.