This has been happening a lot with words, Negro to African American, Indian to Native American, moron, idiot, and retard were all once medical terms, now replaced by mentally challenged, midget to little person, queer also once a medical term, replaced by member of LGBTQ. Many disorders are being replaced by acronyms, ADD, ADHD, PTSD etc.
I think removing the humanity from these words is part of the point, because people are naturally judgmental, if they hear "Operational Exhaustion" they think "Oh, just tired then", not that there is a medical issue. You can't use "mentally challenged" as an insult precisely because it's had the humanity sucked out. Assuming that a term having "humanity" means for it to have emotional connotations.
Words are stretched and tortured such that it's difficult to immediately derive the meaning, which again is the point, to get you to use your logical brain rather than your more emotional lizard brain.
I actually think Post-Traumatic Stress Disorder sounds pretty bad, primarily because it says "disorder," i.e. it's an admittance that something is wrong.
Whereas "Operational Exhaustion" sounds very soft and innocent.
~Oh, that's a good point. Taking the "disorder" out might help the VA in denying treatment for it, and make it seem more like the soldier's fault that they have it.~
~How about "mission resilience depletion"? That makes it seem more like they just forgot to recharge the batteries in their mobile phones. Or "norepinephrine-cortisol disruption syndrome", which makes it sound more like they haven't been taking their pills at the correct dosage.~
I'd say that PTSD sounds the worst, though because it has the very negative words "traumatic", "stress" and "disorder". The middle 2 are the least bad, because "exhaustion" is not that negative.
Shell shock almost sounds like the bombs themselves. SHELL SHOCK. Post-Traumatic Stress Disorder and all the humanity has been ripped out of it.