No new car sales, and PHEVs are included which should solve edge cases. That's very different than all cars. Also, most of CA doesn't get cold enough that any of this discussion is relevant.
Costs. Complexity. You have a large battery, a gasoline engine with a transmission and 2+ electric engines in a PHEV. And they all need maintenance in the long run.
This will be hopefully mitigated when all PHEVs only run the gas engine as a generator and get rid of the transmission, but I don't think we're there yet.
> This will be hopefully mitigated when all PHEVs only run the gas engine as a generator and get rid of the transmission, but I don't think we're there yet.
If it's cheaper then they'll do it.
More generally, you can remove a chunk of the transmission in a hybrid and use a simpler engine even if it's not a generator. The complexity isn't a big deal. And the moderate cost gets offset by significant fuel savings.