Cameras can also *see* cars, fake plates or not. If the ANPR hadn't flagged it right off, there's a fair chance the CCTV guys would have spotted it - and they could just as easily then stick the fake reg into the computer.
There's also a difference between car theives who sneak off with your stuff and car theives who are willing to risk an assault / ABH/GBH charge and the associated police response / prison sentence.
But you're right, we should go back to the police having a truncheon and a whistle and maybe a horse...
I think it's funny that google, amazon, and your bank/credit card probably know waaaay more about you than the authorities do, yet things like this get shit on in the name of freedom. If I get mugged, or burgled, or whatever, I want it to be on as many cameras as possible. CCTV is a massively EFFICIENT and EFFECTIVE way to catch criminals and make the Police and justice system's job easier and safer. With power comes responsibility, and we should be watching the watchers very closely, but not cutting off our noses to spite our face.