GM/Ford/Chrysler have a symbiotic relationship with their dealers - they both need each other to survive. Neither wants to see a new upstart that might someday eat their lunch.

Presumably if the makers had a do-over, they might try direct to the consumer themselves, but the present conditions make that impossible.

Since only Tesla actually wants to sell direct (and in fact needs to due to the unique nature of their product), this does in effect only target Tesla. It just doesn't look so targeted to the layperson, which is likely why they can get away with this.