I don't think we want to describe sexual assault victims as having "shell shock". Even a soldier could get "shell shock" without encountering any shells. The language got softer not because we're all a bunch of softies but because we noticed a general pattern and generalized the name to match.
There are certainly times when shell shock makes no sense but I find PTSD dehumanizing especially since no one actually says post traumatic stress disorder.
I agree "shell shock" wouldn't suffice but you could just change his word to "past-shock" or something, and notice how different that feels than an 8-syllable medical phrase.
I do think putting big fancy words on things implies a fake level of understanding, takes the word away from everyday users, and has other real effects.
Either is possible, but I think you are wrong about Carlin being wrong. Language defines the quality of our conversations. If we can't be honest with it, some nuance will be lost.
It may help to think of it as a range.
It is sort of schrodinger stragety - you make claims and if someone strongly argues back, it was joke. If there is no strong pushback, we pretend it was serious.