I actually don't dislike the people in the movie, and almost feel bad for them in a way.
I watched this last night. I found the couple less sympathetic than you do for the following reasons:
1) David Siegel and son made no bones about the fact that they used psychologically manipulative tactics to sell people time-shares they can't afford. Their cynical, rubber-hits-the-road, involvement in inflating the credit bubble makes them even more culpable for the financial meltdown than mortgage bankers in my opinion (if in spirit rather than in scale).
2) They were totally complainypants when things went wrong. They actually blamed the bankers for giving them too much credit. Unbelievable.
3) Meglomania. One of the opening shots when Siegel brags about using potentially illegal tactics to secure George W's win in Florida was just a sick display of a probably delusional grandiosity. He seemed to think it was pretty cool that he "caused" the Iraq war.
On the other hand, I have to think these people differ from so many others not by their attitudes, but on the scale at which their ambitions play out.
Overall the documentary was pretty fascinating. It's filled with moments of cognitive dissonance (David claims he doesn't care about material things while building a $100 million house filled with expensive kitsch), strange playing to the camera (Jackie feigns surprise that her Hertz rent-a-car doesn't come with a driver when she's "slumming it" post crash), and awkward glimpses into the life of a rich man and his trophy wife (Jackie desperately loads up on plastic surgery to please her husband who hosts Miss America pageant contestants at his house because he "loves beautiful women"). I felt especially bad for their many kids who seem to live in a world of unstructured, chaotic excess.
If there was ever a demonstration that material things aren't going to make you happy, it's this.