I think many people enjoyed the book and took most of it at face value, but it was clear that a lot of readers were sceptical too.
I said on another thread that I don't think they are necessarily bad people but they come across as amoral, rather than bad.
DH has a friend just like this. He doesn't set out to do bad or wrong things, but he doesn't lose any sleep if sometimes that's how it pans out. He was always brilliant at setting up businesses, worked hard at them, very creative thinker about how to sell the business - but tragically, hopelessly useless with money. Many people lost money, including friends, investing in him. A business would fail and he would just do a runner leaving everyone else to take the hit.
People like this tend to despise their sensible, boring friends who settle down with marriage, and kids when younger, and get all mealy mouthed when, forty years later, their friends are quite comfortably off and they have nothing.
These remind me strongly of this friend