I agree that I'd rather see Castillo getting time over Young... but I do like Holt as an everyday player. Holt can still be moved to the infield when needed then our 4th outfielder can come off the bench.
The question for me is when a bench fill in is not needed for the infield (the majority of the time) who do you want sitting on the bench not contributing...Young, Castillo, or Holt? No brainer.