While you are right, it is an exceptional scenario to earn that kind of money. So it is statistically insignificant to calculate absolute income minus rents etc.
It's quite significant even within much more common ranges. If you make $60K/year and spend 25% of it on rent, you net nearly 20% more than someone who makes $40K and spends 5% on rent. Looking solely at percentage of income spent on housing will lead you to a very wrong conclusion in that circumstance.
