Whilst I understand all the angst over the fraud on the software of the pollution device, I don't understand why you would give back what was a really good vehicle rather than just take the compensation. Then again I don't understand the vehicle herd mentality that some in the USA have.
Garry, not certain what you mean by the pejorative "herd mentality" that some have in the USA, but in reality, the situation was merely a blip, a speedbump in overall VW sales in the USA, with the bulk of that in 2016.
http://carsalesbase.com/us-car-sales-data/volkswagen/ Diesels in the USA have always been just a small fraction of overall motorcar sales. There are a variety of reasons for this, such as [generally significant] increase in initial cost, and wildly fluctuating disparity in fuel pricing. Anecdotally around here (Michigan), diesel has always been higher, and that high fuel price negates the other savings. Today, one local retailer is at USD $3.07 for regular (87 octane) and $3.29 for diesel. I've seen that differential as high as $0.40 per gallon, particularly during a cold or potentially cold winter when home heating oil (used extensively in the north east) prices go up. Home heating oil is basically #2 diesel. Due to fuel pricing and taxes the payback on a diesel in Europe is significantly quicker than the USA; that won't change easily, and thus the mix of diesel/gas won't either. With hybrids and electrics all the rage, I'm not sure diesel will make a comeback for passenger cars in the USA.
I cannot speak for the population that had these [deceptive] TDIs but presumably some bought them because [amongst many reasons) they thought they were being "greener" than other choices, thus when the scandal emerged the only sensible thing to do was to get rid of it. I'm sure there's a subset there that simply loved diesels (to heck with emissions) and took the money. Others didn't want to be "caught" down the road with a car that they might not be able to sell.
As an interesting analogy, in the early 1990s many new homes in the USA were sided with "LP Inner Seal" OSB siding, which was basically an inferior product that was cheap. It failed miserably, and there was a huge class action lawsuit to recover damages. There were a lot of homes in my neighborhood with that junk on it; some owners took the money and did nothing. Others took a settlement and re-sided their homes. Those that took the money and did nothing found themselves in a bit of a bind when they went to sell their homes; they basically had to give back what they thought was a windfall from years earlier.
https://en.wikipedia.org/wiki/Louisiana-Pacific In the worst cases, the cost to re-side had gone up and savvy buyers required the sellers to make the change prior to closing.
So is "not wanting to own a product not living up to specifications" and one that will probably be difficult to sell down the line, a uniquely American trait? I wouldn't think so, sounds like human nature to me!