Psionics is as medieval and fantasy as swords or dragons. But why it doesn't seem so is the historical oddity of Europe being under the control of a monotheistic religion which didn't allow for alternative belief systems. Essentially psionics are how people who have monist elements to there belief systems explain the occurrence of controllable supernatural happenstances.
Sufism, Yogis, Gnostic Christians, Buddhist all fit well with in the psionic realm.
As far as adapting psionic to be a variety sorcerer that just seems to be cruel. Those who use psionics have always had there own system, which in itself expresses psionics better then to the vancian system. To others less concerned about flavour it provides opportunity to play a non vancian caster.
I can understand psionics not being everyone’s variety of fun. But it is my variety. And has just as much place as Rakshasas, ninjas, splint mail, wish spells. All of which are non european but have found an unquestioned home in the game.
