Yes, diesels are nice, the reason they are a dead-end as well is that they are also filthy and inefficient at low RPM (hence the need for a turbocharger in most passenger vehicle applications).
You have the sensible application of diesel engines exactly backward. Diesels are used in commercial application because they produce huge mountains of torque for heavy work.
Actually, ELECTRIC drive blows Diesel away, even in the low end... which is exactly why DIESEL-ELECTRIC is how every large vehicle is built.. whether it be Railroad or Earth Movers, and why Diesel-electic should be applied to things like Busses and such, and is being used in test cases around the country now.