Because the self diagnosis is largely made up by people who don't understand what PTSD even is. It's like someone declaring they have cancer without going to a doctor.

> Why would you react to it having been “made a mockery of” by reinforcing this supposed mockery?

Because it's become part of the lexicon now. I don't think there's any going back. My usage was the "new" usage, no relation to PTSD was intended.