Your definition of optimality is based on expected values, right? Well previous to your excellent point of burning service time on the DL I didn't really see how this move moved the needle one way or the other, so as a fan I was just excited to see a player in very optimistic for (and I will always favor major league call ups because I principally hate the current service time system that incentivizes teams from playing their best, most exciting players).
But even with a very small possibility of injury, the potential downside is so enormous such that it outweighs any superfluous upside possibility. So thanks ensheff, now I have to watch tonight's game with a small bit of contempt.
Oh I'm still going to enjoy watching, just like I enjoy watching Swanson and Albies. I made a point to see all MLB debuts of the young pitchers (Newk, Fried, Sims). I can still be a fan while criticizing the moves made by the FO. Most around here think being a fan is spending your free time on your knees in Coppy's office licking his boots while telling him how great his bald head looks, but that isn't so.
I want to see a LHed Folty out there tonight, which is how Gohara has been billed.