To be fair to the powers that be, 9-11 and everything that followed didn't help the scanning industry any.
"If you see something, say something" = "I saw this dude carrying a radio listening in on the cops, I think he's a terrorist..." Exaggeration, yeah, but I think 9-11 put the idea of monitoring police and other agencies in a new light.
I think a lot of enforcement agencies simply do not like the idea of being monitored, in any way, period. And now they have the tech available to prevent that. If I were in their shoes, maybe I'd feel the same way.