It’s not the local government putting them up, it’s a private company who is in charge and keeps at least half the revenue. Plus when their location is known and they get less effective the same company will try other things like altering yellow light time length to keep profits up.
We don’t like the idea a private company is enforcing laws not for safety but for profit. Especially when things like shortening of yellow light time and cameras that don’t properly report speed. It’s horseshit.