I think you're missing the point though. These are people who aren't optimizing for quality of life as most people define it (i.e. work as little as possible and reap maximal rewards and time with people you care about). Work / achievement / solving problems / obtaining resources becomes the goal itself. It is never enough because you can always have more / there is always something else to do / there is always another problem to solve / there is always another company to start etc.

Its the same thing for people who are serious about the gym. You can deadlift 600 lbs? Cool, now its time to try to get to 650. If you hit 650 it is time to plan for 700.