My take on it is that it’s just a system run on laziness by both parties. The city knows red light cameras are BS, but it just wants you to get scared and pay the ticket so they and their accomplices (the companies who build these automatic cash machines) can get their money. Send out an official looking notice with photographic evidence and scare the mark into paying up. The victims of this scam just want to pay it and get it over with and are afraid of ignoring the notice and/or appearing in court.
This is not legal advice, just me bitching.
And no I’ve never gotten a red light ticket.