You laugh, but there's been more than one debate on these boards about how psionics is/isn't "magic" and people could get hot around the collar about the distinction. Things have cooled down a bit in the past couple of years, but I remember when it was a Big Deal.
But I don't know where they are coming from, with that whole "Dark Sun is science fiction" angle. Words mean things, and I don't think they read up on
what sci-fi means.
Here's my thing on Psionics: It's not magic. Unless it's the only supernatural power, in which case it might as well just be magic.
Magic exists within a storyline as a set of rules and functions that are separate from normal physics and mortal capability. A mortal can learn to use magic to jump 90ft in the air and land safely, but a mortal cannot learn to -just- jump 90ft in the air and land safely. Supernatural power, in a nutshell. Whether from a Metaphysical Source or some Physical Source or whatever, it breaks physics as we understand it.
These rules and functions tend to be things like magic words you recite, special gestures, icons or items that you use to either direct the magic or as sacrifices to the magic, and it's typically organized into a series of different "Spells" which are basically a how-to guide with specific outcomes.
Psionics, or indeed any other supernatural force that is "Not Magic", exist outside of Magic as it has been previously defined. And are thus separate from magic. Another force in the story. They don't follow the same rules as Magic, often shunning the use of words, gestures, and icons or sacrificed objects or creatures, because this sets them apart even when their "Powers" are basically still "Spells".
You could then bring in Ley Power as a third force which is "Not Magic" but still fulfills the supernatural functions of magic through a different set of rules. Maybe this one has words and gestures, but not "Spells" at all and instead it's practically a firehose of power you just kind of direct at different levels of intensity or something.
Because once you have the rules defined on what Magic is you can define other things as different because X, Y, Z reasons. But without "Magic" you cannot really have "Not Magic" supernatural power. Because Magic is practically the baseline human understanding of "Doesn't conform to physics".