SDM44
.
I call BS! Please provide proof. I've been to all of these places. They capture your rear plates and actually have it printed on your parking ticket to prevent fraud. Electronic toll cameras also grab rear plates only. I have not ran a front plate for 2 plus decades and have not been denied entrance to anywhere.
Maybe not in the Bay Area where you're at, but in So Cal when driving into LAX the police out front have and will ticket you for not front plate if entering in to pick somebody up or to drop them off.... same with front window tint. This may not happen all the time, but they've announced it in the past and it still happens. Same with parking in the LAX terminal parking garages, or in any of the Metro train parking lots, where parking enforcement will go around and ticket you for no front plate.
Most of the time you will get lucky and not get caught, so it's never a problem until it finally becomes a problem.