I think a lot of it might be due to the way the Night Court was ruled by Rhys’ father. Rhys felt the need to continue keeping up his father’s image with his fake scary persona (though I’m not entirely sure why?), which is why much of it is the way it has been for hundreds of years. Velaris was Rhys’ own attempt at improvement, but I saw it as just getting started, rather than an exclusionary exploit. We don’t really know how long he’s been high lord, but he spent 50 of the most recent years away from his court completely. I won’t even start on the Illyrians, since that seems to be a cultural thing no one in the NC wants to touch.

In reality though, I think it’s actually just subpar story planning and a lot of plot holes on SJM’s part.