I suggested earlier that the TNG-era shows never depicted human telepaths because belief in human telepathy had declined since the 1960s. But once I wrote it, it didn't quite sit right to me, because there were other contemporary shows like Babylon 5 and The X-Files that still embraced the idea of human telepathy.
So it just occurred to me to wonder if the real reason is just that the writers of the TNG-era shows got too used to stereotyping species by their defining traits. You want a warrior character, it's a Klingon; you want a capitalist character, it's a Ferengi; you want a telepathic character, it's a Betazoid or Vulcan. So it just didn't occur to them to write about human telepaths despite TOS having established their existence. Humans were just the baseline, ordinary species you used when you didn't need a character with special abilities. By contrast, TOS focused more heavily on humans, especially early on, and had few alien species that appeared more than once. So if they wanted to do a story about a character with psi powers, there was a greater chance it would be a human.
