No one with a family will buy such a thing.

Diesel fuel is likely to become cheaper than gas in the future due to refining capacity issues. There have been no new refineries built in the US in over a generation and only one or two in the works going forward. All new refining capacity in Europe (which supplies much of the refined produce for the US North East) is diesel with no new gas refining capacity planned. Elsewhere in the world diesel is the likely target of new refining capacity available for US shipment. It's supply & demand from there.

Most of Europe has a much higher population density than any part of the US except some parts of New England etc. I can't recall ever seeing statistics on how far the average European lives from work, but I do know that Americans change jobs more frequently so are likely to not prioritize buying a house near work as highly since they aren't as likely to stay there forever. Most middle-class Americans give first priority to quality of schools in choosing home location and are willing to sacrifice a lot of commute if there is a big difference in school quality.

What is the mileage with air conditioning on? Claims of stellar mileage if I would just leave the A/C off carry little weight when the temperature exceeds 110F.