Totally ridiculous specifications that are driven by marketing departments, not engineering departments.
Diesels get better mileage, that helps with government mandated fleet fuel mileage averages. High mileage vehicles offset the lower fuel mileage vehicles that are high profit for most manufacturers. Keep looking and you will soon see diesels trending toward what is in Europe -- smaller and very good mileage. They will be everywhere in America. Clean, quiet and economical just like the VW TDI Jettas. VW has had it figured out since the days of the diesel Rabbit back in 1975 and has refined the diesel to where it is today. One $150 battery and it gets 45-50 mpg; the hybrid Prius gets about the same mileage on an $8000 battery.