Good summary. I agree, the only reason to pay the $15 fee would have been for access UP the Whitney Trail. People were paying the fee for other reasons by mistake, as reported by Steve.
The other issue not discussed is the people who got the PCT LDP as a work-a-round to the lottery and open pass to climb whenever. That was a dirty little secret I know some people were doing. I suspect that was the "incident" or "incidents" that drew attention to this matter. But again, I'm only speculating here.
