I disagree with a couple of your points,
First there is lots of people with demanding careers or businesses, they may have young families, they may spend (and have to be "on") for 60-70 hours at work a week, and/or days away from home. They may make salaries over 250,000 + a year. Saving ten thousand dollars or more may not mean anything to them, all they may want is time to be with their families.
For those people time to be with there families are precious, the last thing they want to do is spend time looking at resales, or renting points.
Yes I do believe many of these people would want to own a DVC membership and not just call for reservations. Maybe not all but a sizable percantage will.
To these people DVC is not a financial investment, they may see it as an investment in mental health, though.
We see this all the time, people buy expensive cars, mansions, diamonds, boats and whatever.
For many people if they didn't spend it on a DVC they would have spent it on something else, for many people 10,000, 50,000 even a 100,000 is spendable income. We may think of them as crazy spending all this money, but they may think we're crazy for working for so little. So who are we to judge when someone buys a DVC at retail?