> Edit: As a side question, if they really prefer a different distribution of work, why do we as a society punish them for it by valuing that work less than we value work generally done by men?

I think you are 100% mixing up correlation and causation. "We" don't value anything. The market places a value on things based on what individuals are willing to pay, and has no knowledge or care about the gender of the person performing the task.