I don't know how related this is to the article, but your point is true. As an example: it's been posited that a portion of the gender wage gap is due to the average height difference between men and women. Why? Because there's also a "height wage gap" between tall and short men, to the tune of thousands of dollars a year comparing either side of 1SD from the the mean. By not taking wage gaps seriously (because they're largely spoken of in terms of gender and race), short men are robbing themselves of a payday, and tall men lose out on the social stability that more equitable pay would bring.
Inequity doesn't just affect any particular group; its mere existence changes the way we think about what's fair and tolerable.