California announces that the policy is going to expire. People who paid more and had an expectation of never-ending special road access are angry.

This is the step where your comparison to solar (at least in California) breaks down. I'm not a California resident, but from what I understand under the NEM 1 and NEM 2 rules there is NO expectation the preferential net metering will last forever. Solar customers were specifically told that putting in solar during NEM 1 would guarantee those terms for 20 years from install date. Same thing for NEM 2, the rules would apply for 20 years from the install date. After the 20 year period, you'd be subject to whatever net meter would be offered to new customers, which could be none. source

What this proposition proposes is cutting that 20 years to 10 years from install date:

"Convert NEM 1.0 and 2.0 accounts to the NBT either upon sale of a home or after 10 years of interconnection. " source

So customers that took a large financial risk installing solar that are coming out ahead may now have the deal shifted out of their favor. How is that fair to the solar customers? Worse, the knock on effect will destroy the trust in state government incentives in the future. Why would any citizen risk a long term outlay based on policy if the state government may decide one day they don't want to hold up their end of the deal anymore?