Being the owner of diesels in the past, here is what I loved about them:
1) Easy to work on and maintain. Start to finish, it took 20 minutes to replace a water pump including coolant and serp belt.
2) Easy to modify for more power. The engines are stout and with the right tuning you can increase boost and fueling with little effort or money while maintaining reliability. I increased the boost and changed the fueling for a total cost of $0, the only money I spent was for the exhaust shop to straight pipe it.
3) Longevity. I put 30,000 miles on the truck in one year, by the time I sold the truck it had 170,000 miles on it, many of them towing miles, with a total of MAYBE $150 in repairs, all of which I was able to do myself and none of them took more than 30 minutes each. It ran like a champ, didn't burn or leak oil (Other than the diesel in the tank.

), and towed like no other.
I would go back to diesel in a heartbeat. Better mileage, better for the environment (emissions-wise), better resale value, tows anything like a dream. The lowest MPG I got was 17mpg while towing my Jeep on a flatbed trailer. Unloaded I would get 20-22mpg on the freeway and the truck weighed in at 6500lb (rounded up, I did have it weighed on a scale).
Now that people are able to make their own fuel at home using WVO there's an even bigger group of people wanting to get a diesel, be it a truck, a Benz 240D or 300D, VW Rabbit (old) or newer TDI.
What I don't get, to a point, are people NOT wanting a diesel or people that are against them for no good reason. There are more positives than negatives to diesel. The biggest negative being initial cost, but again that is recouped by having a higher resale value.