The subjects of this article never said anything that implies that they don't know what a marginal tax rate is. It profiles a lawyer and a dentist, two profess

The subjects of this article never said anything that implies that they don't know what a marginal tax rate is. It profiles a lawyer and a dentist, two professionals whose pay is in proportion to the hours they put in, who have to decide when the marginal value of more money is less than the marginal value of more free time. Naturally, there will be a cluster of people who decide that the tax bracket change point is the right place to do this - more so the larger the difference between the two brackets. Or, to use the tone that the author used, this idiot author is so stupid that he doesn't understand the concept of marginal utility...