Well, if you think the EV market is saturated at less than 3% of vehicles sold in CA...then the EV market will be a niche market UNTIL the government acts...GM and others are pretty good at marketing. Having them spend more and do a better job explaining these wonderful vehicles isn't likely to lead to big changes in the proportion of EREV or BEV vehicles on the road.
People vote with their wallets, and they'll vote for ease and convenience. The easiest, most convenient and cheapest vehicles to this point are ICs.
I love my Volt and, now living in CA, I'm not alone. But even there, the market seems saturated as sales have stalled.
BEVs and EREVs can be promoted best by government (think regulations that eliminate or discourage ICs). But who wants that?