But are small, cheap cars selling? Like in any meaningful numbers? GM sold fewer Sparks in all of 2018 than Toyota sells Camrys in a month:
Automotive Sales Data and Statistics
www.goodcarbadcar.net
And if you look at the trends, Camry sales are down 22% since 2015 (following the trend of all sedan sales).
If you can make profit on small cars, but you can make more profit on other things, why waste time on the small cars? There are huge fixed costs in vehicle manufacturing. Materials. The amount of metal in a base model Fiesta and a Platinum trim Fiesta is the same. Engineering. The engineering costs for the general structure, powertrains, etc of a vehicle are shared for all versions of that vehicle. Labor is a huge cost in a vehicle too, especially for domestic makers that pay assembly workers high UAW wages and benefits.
If you want to maximize profit, then you sell the most profitable versions of the most profitable vehicles that you can. It takes roughly the same amount of labor to build a base model F150 as a loaded, Limited trim truck. But that base F150 might make them 7% profit on a $25k truck, for a total of something like $1750, while the Limited trim makes them 10% profit on a $70k truck for a total profit of $7000. You can make money at the bottom, but it pales in comparison to other options. The examples above consider profitability of different trims within a model, but the same thing can be done with comparing different models. If you make $1500 profit on a low trim Fiesta, and you make $1800 on a low trim EcoSport (which is really just a lifted Fiesta), then you push the vehicle that makes you more money.
Markets change. Customer expectations, government standards, the people in society that have the money and need to buy, etc all change over time. I see a ton more half ton trucks than new mid size trucks, because the half ton trucks have gotten so good that the benefits of a small truck aren't as significant. For pretty much the same money, you can get a vehicle that's more capable, nearly as fuel efficient, etc.
See point 1. They're not really selling well relative to any other market segment. And ultimately, it doesn't matter what I think or want. The automakers are going to do what's in their best interest not what's in yours or mine.