The "these examples" in the footnote refers to the preceding content in the main part: the example of Bill Gates, and: > There are even some people who have a

The "these examples" in the footnote refers to the preceding content in the main part: the example of Bill Gates, and: > There are even some people who have a genuine intellectual interest in making money. This is distinct from mere greed. They just can't help noticing when something is mispriced, and can't help doing something about it. It's like a puzzle for them. He's just saying that people who are especially interested in making money are likely to make more money (just as say, people interested in listening to music are likely to listen to more music). (No comment on whether this is a good point or a satisfactory explanation of economic inequality or whatever, just explaining the point of the footnote, as that's what you asked.)