Everything in here matches with my experience in the auto industry, but I don't think it gets the whole truth. Car companies, particularly the American and German brands, make the vast majority of their money from new car buyers and leasers, not the used car market. Over the past few decades, OEMs have focused almost exclusively on serving those customers, to the detriment of virtually everyone else. Those are very different customers than the people who want to buy $25k cars. Worse, even if you do sell that kind of vehicle, it depreciates and goes right back into circulation on the used market competing against the new cars because the customers are ultimately very utilitarian and lack brand loyalty, unlike the higher end customers. You can't even count on those higher end customers to reliably purchase the higher trim models because of the "status" aspects of a cheap car.
It's a tough market that OEMs don't want to be in, so they cede it almost entirely to foreign OEMs that haven't moved upmarket yet. Foreign OEMs are structurally incapable of selling cars at those prices (by design), so the bottom end of the market gets hollowed out to nothing but a few "loss leader" vehicles.