A few problems:
1. Diesel is more expensive than gas outside of interstate truck stops
2. Not every gas station carries diesel
3. Diesel parts are expensive; Honda's not saving any money over something like an Ecoboost 4cyl since you still need a turbo and forged parts
4. Obnoxious repair costs (a broken injector is much more likely to cause catastrophic engine failure)
5. Additional maintenance and hidden costs (frequent fuel filter changes, more engine oil per change, dual heavy-duty batteries, etc.)
6. 75% of owners are idiots who do not read the owner's manual. They will get their oil changed at Jiffy Lube-type shops who will use regular motor oil instead of the correct diesel rated oil. Hello sludging.
7. Diesel MPG's have been dropping due to the whims of the EPA. Some manufacturers have gotten around the use of urea by dumping excess fuel through the motor during regen cycles. I would rather add a bottle of urea every oil change.
I'm not trying to criticize you individually, and your perceptions are of the average person.
#1: According to the US Energy Information Administration the average cost of a gallon of gasoline on October 24, 2011 is $3.462 per gallon. The same info for diesel is $3.825. When we compare real numbers of fuel efficiency of diesel vs. gasoline we generally end up with diesel being about 27% more efficient than gasoline. Diesel fuel contains more energy per gallon than gasoline and lends itself to more efficient delivery and burn processes. So using that number we find that if we paid $3.825 for a gallon of diesel fuel we should only pay $2.792 per gallon for gasoline. So the price of gasoline is the one that's out of line, not diesel.
#2: I agree that not every station carries diesel fuel. This varies considerably by location. In my part of the country it's unusual to find a station that doesn't have diesel fuel. As more and more diesel powered passenger vehicles come to market you'll find this problem (if it really is a problem) will vanish. Keep in mind that you will need to visit the fuel station fewer times in a diesel powered vehicle as well.
#3: If we use VW, BMW, and Mercedes Benz as real world examples I think you'll find that the repair costs are lower, and reliability and resale value are higher on their diesel powered vehicles vs. the essentially similar gasoline powered vehicles.
#4: Since there's a rapid movement to GDI (Gasoline Direct Injection) I think you'll find the costs and potential engine damage are the same as diesel. GDI is essentially a diesel injection system on a gasoline engine. Moot point.
#5: Again using VW, BMW, and Mercedes-Benz as examples I think you'll find the maintenance cost is very similar to the gasoline counterparts. Most have 10,000 mile service intervals which is longer than the average gasoline engine. Fuel filters are essential, but that's really a problem with our low quality diesel fuel in the USA. Things are getting better. As for batteries... I think you're comparing apples and oranges. Passenger car diesels don't use dual battery systems.
#6: I think this applies equally to all owners. As for sludge... talk to Toyota owners about that.
#7: As I pointed out in the original post... manufacturers have good reason to believe some of the unfair EPA diesel rules will soon be changed. I think we'll see urea, diesel particulate filters, and other nonsense removed from passenger car diesel regulations within the next 2 years.
I challenge anyone to drive a modern diesel powered vehicle and tell me they don't drive better in nearly every respect than the same car with a gasoline engine. Nearly every review of the VW Jetta and Passat point out that the TDI is the version to get. Same with the Mercedes-Benz offerings.
Better fuel economy, better reliability, fewer fuel fill-ups, and higher resale value. That's reality. From the numbers I heard in 2009 the Ridgeline would have been rated at 27MPG highway and 20MPG city with the V6 diesel. The premium was $4000 which would have dropped if production increased. You could reasonably say a diesel would be worth at least $2000 more on the back end resale if not more. It's a no brainer... diesel is a good thing.