Well, back to the original question since I in part derailed it. I bring this up with some embarrassment (because I am not very good at it), but I do some fiction writing including sci-fi (not at a level to call myself a writer).
I don't think I would include human psychics in a story outside of them being an anomaly or maybe as part of a very "special" very small group. It's easier to go with aliens...and even then I suspect I would stop at empaths (but not the Troy type). The issue for me is multi-fold.
First, humans (us) tend to have poor views of human psychics. Putting aside the issue of if they even exist, our culture (generally) views them as charlatans of freaks (and I mean no offense to anyone). In Sci-Fi they are often portrayed as very flawed or even bad folks. I think our cultural view of them (or the concept) is part of that. Even looking how they were treated in B5 - they were shady. They work better in fantasy IMO. Or aliens are more believable. Even thinking how I would write one into a story believably, I end up with a trite character of limited use. Unless of course I make a small band of them.....I think I could do that maybe.
Second, is the human condition. A lot of what make Sci-fi interesting is how it explores the human condition. Most readers may not catch it, but it is there. Can you imagine how boring Star Wars would have been if it were just about Solo and Chewy zipping around running from bounty hunters - never evolving - day in and day out? (OK, they are not human...but you get the point I hope). There needs to be some evolution/exploration of the human condition. If you make "humanity" in a story too far from what we are now without some serious background and justification, it becomes too hard to relate. There is actually a book series I have read where there is basically no plot. But they are interesting to read because you want to follow how the main character evolves.
Lastly, and someone already said this and I disagreed with their reason but I agree with the premise, it's too easy and leads to story holes. If "Jeb" can see through walls on page 8 when the story needs it, then on page 57 when the story is better served without that ability, there has to be a contrivance. And too many of those make for hard reading. And if "Jeb" meets with dozens of wall during the story....it's a problem.
Anyways. That's my uneducated opinion on that, but it might explain the issue.