Society as a whole did this to themselves.. women wanted to become better educated, work better jobs, get paid more, more equal rights.
They got it and now they are just as much of consumers as men. Guess what, everything from the 60s on saw products get a lot more expensive since that movement because companies know that people have dual income households. Now we backed ourselves into a corner with high housing prices, car prices, etc. because now marketers can target twice as many people. It's rare now that a single earner can carry the earning burden for the family of four. We've made it so that both people have to work now.
Regardless of what their target audience is, women are going spend money at an equal rate, regardless of what men spend their money on. Just so happens, what women do after the house and car note is paid, is typically different from what a man spends his money on. So I get the disposal income target being the same.
Simple cause and effect here. You make your bed, you lie in it.