Well Greater Manyshot isn't the only feat that asks the "Why is this psionic" question. I have two theories: 1) The needed to pad the book a little. 2) Bruce R. Cordell had a bunch of feat ideas and couldn't think of any other book to put them in.
I lean towards theory 2, because I see feats as an inificent word count to work ration.
I lean towards theory 2, because I see feats as an inificent word count to work ration.