Obviously it can be a bit of both. I’m sure a lot of those guys on Wall Street get off on the high stakes, competitive environment along with all of the benefits to being wealthy. On the other hand, some people choose jobs that don’t pay much but give them a high degree of satisfaction. But I surmise that most people, particularly men, are mainly motivated extrinsically in their jobs to provide for their families, to maintain a certain lifestyle, or simply to survive.
It’s perfectly possible to have both a reasonable salary as well as intrinsic satisfaction.
However, I will say that getting both of those characteristics together is far more likely with a skilled job compared to an unskilled job (i.e. jobs that require specific training and/or degrees).