The flaw in your analysis, and your linked article, is following the fallacy of Homo Economicus, which is "an arbitrary definition of man, as a being who inevitably does that by which he may obtain the greatest amount of necessaries, conveniences, and luxuries, with the smallest quantity of labour and physical self-denial with which they can be obtained." http://en.wikipedia.org/wiki/Homo_economicus

In reality, humans rich and poor alike have many considerations of equal or greater importance than their utility function. For example, people not work full-time because they are in school, because they are practicing an art or craft, because they are taking care of family, because they have a wealthy benefactor, because they are employed in an illegal trade like drugs or prostitution, or because they are trying to break into a difficult industry like film.