Why aren't people removing these cameras?

This is big data.
Like, people have talked about big data, people think they know what big data is.
Big data is the kinda thing that lets target know a shopper is likely pregnant then act on that information.

The difference is that a company has leveraged this against a different kind of public information - physical information (licence plates, in this case) - and developed and deployed the tech to gather the relations of that public information (alpr/anpr cameras), and has made it commercially viable (selling a useful analysis of that big data to police).

Maybe they sprinkle in some AI to help with pattern recognition instead of having to rely on data scientists to do their wizardry. Maybe that's what makes this finally viable. Replace the expensive analysis with AI stuff.

But there is nothing new new here.
Alpr/anpr has been used to track cars for ages.
On the small scale, making sure people pay for parking/tolls/speeding/congestion-zones.
On the medium scale is just logging that data, and letting LEA query it (with a warrant?) to track a vehicle.
This is now on the "big-data" scale. This is matching patterns against events and drawing conclusions.

Oh no! Who would've guessed...