Because of historical precedent. GM is fully aware that their plug-in vehicles are more expensive than the average car buyer will spend, so as they improve efficiencies and reduce production costs, they lower the MSRP. They did the same with the Volt, which started out as a $40,000 car and was quickly reduced to a $34,000 car.
Right now, they are already doing a "soft" reduction of the Bolt EV's MSRP through rebates, so it's simply a matter of making it a permanent reduction in MSRP.
Yes, but if you compare to pickups, sale prices have about double the difference off MSRP, meaning 8-16k off is fairly typical, and that's on the still a truck version. If you look at the gussied up version, I believe the discounts are higher, but I don't care, because anyone who buys an 80k truck probably doesn't even know where an unpaved road is, much less, ever drives on one (insert scene from Cars movie here).
Some people pay MSRP, so if you reduce it, you're loosing dollars, not just for GM, but for the government, too, as tabs are based on (alleged) value. Insurance, too, often keys off MSRP not real sale price.
I would like to see MSRP reductions, but I expect there will be more rebates, which will likely be spotty.