PC, in our case, it's very simple. The occupation I'm in pays more than the occupation my wife had when we had children. (Electronic/industrial maintenance vs newspaper advertising). Doesn't matter which was in which profession.

As she had the lower wage job, she cut her hours back to allow me to work more. It's just economic common sense. Had it been the other way around, I would have removed myself from the OT list and stayed home more.

There's no conspiracy, folks. Move on.