No: John gets the prize, but not because a stabilator is a better concept for slow-moving aircraft (
). Rather, as he indicated (and as englishal seconded), it was simpler, and therefore cheaper, for Piper to manufacturer.
It is true that the use of stabilators is common in jet fighters, and so may have influenced Piper's marketing people ... but I doubt that this was a major factor. John Thorp and Fred Weick were the designers, and both men were known for prefering simplicity whenever possible (remember that the PA-28 had 400 fewer parts than the PA-22 that it replaced in Piper's line-up).