IMO, diesel is still a hard sell, particularly in the US, due I think to:
1. the crappy diesel engines GM made in the 80s or early 90s,
2. the poor quality of diesel fuel itself, and
3. price differential to gas often not enough to justify, and
4. there are far fewer diesel pumps than gas pumps, and finally,
5. the old image of diesel being dirty and smellly.
It will change over time.