Is it? How else would you compare all sorts of metrics between countries with disparate populations and at different stages of development? Per capita is how apples to apples comparisons of income, standard of living, consumption, etc. are made. It is much like using percentages and if one can't understand such simple metrics then they can be easily misinformed as is all too often the case.

A simple example would be comparing Alaska pilot pay to AA pilot pay. Obviously, we would not use how much each airline pays in total pilot compensation, would we?