Right. But there is also thesaurus, and sometimes words don't actually mean different things, and that's the case with psionics. If you levitate things with your mind, you're using magic. And it also is utterly ludicrous to think that people in the setting wouldn't see it that way too.
A wizard conjures a rock to fly. People in magical fantasy land: "Yeah, that's magic."
A cleric prays a rock to fly. People: "That's magic too."
A bard sings a rock to fly. People: "Definitely magic."
A psion meditates a rock to fly. People: "No magic at all going on here."
I'm willing to accept that psionics can sensibly defined as certain type of mental magic. But it cannot be sensibly defined as non-magic.