There is also the thought that if they want free money from DHS & FEMA to pay for the upgrades and radios, they are required to encrypt LE communications as part of the deal. Fire & Med is optional, although a lot of systems are now encrypting the unit to hospital comms for HIPPA security.
Don't give up all hope! many systems that go whole hog on encryption are coming back off when they start having interop difficulties with mutual Aid. In Maryland when the FiRST system when up, Dept of Natural Resources (DNR) went fully encrypted only to turn it completely off 5-6 months later when they couldn't talk to each other, and to other users on the system, like State Police.