Sad yes, except that as I mentioned, poorly-maintained diesels will pollute much more than an equally-neglected gasoline engine. The emissions are also much more harmful due to the sulfur content, hence pollution is very much an issue. Once again, it's up to the manufacturers to create engines that can meet stringent pollution controls... and up to fuel companies to make cleaner fuel. And, it's up to states to legislate that manufacturers comply with these regulations.

(A diesel/biodiesel combination fuel can, in a properly-tuned engine, produce fewer emissions than diesel or biodiesel alone, and possibly even lower than gasoline alone, as well. But legislation doesn't demand such engines, manufacturers don't make them, and consumers therefore don't know that they should want them.)