No that really isn't the only reason. What if he's not hitting? What if the vertigo returns? What if at the only positions he can play, those spots are filled with guys killing it? (2B, 3B). What if he shows no aptitude for CF? What if he does show an ability to play CF, but it takes 2-3 months before he shows it? What if suring that 2-3 months, Puig and Schebler are crushing it, rotating in CF and RF?
Last year he may have been ready to hit major league pitching. He still had no position to play and the Reds seemed dumbfounded as to where to play him.
It's not as black and white as you are making it.