The cameras are sold as a service, so the companies only make money if there are enough tickets for the municipality to justify the expense.
But yes, city hall is slimy as well. Citizens do not get any say in the matter. Citizens do not get to vote to add red light cameras. You just see them going up, and fighting them is a long, hard road. Some cities in Texas have finally banned them, fortunately.
Redflex/etc are definitely profiting plenty off of the devices. No question about that.