Yeah, I guess that would explain why Hornacek wasn't on scholarship until his third season.
The main reason for Jeff's NBA career was that he went to Phoenix, and the Suns were absolutely desperate for guards at that time. That's the only reason he made the roster, had a chance to retool his shot--and eventually went on to a lengthy career.
I used to work with a guy who played with the Suns. He didn't know I went to ISU, and I asked him what he thought of Jeff Hornacek. He said <paraphrasing> "woo, that guy could put a pass anywhere and it came rocketing at you right where you wanted it."
So no, that's not the only reason....