From what I have seen, the real issue is emotional support.

As far as chores - if the wife is cooking and cleaning while the husband takes care of the yard, the car and home repairs - even if she puts in more hours, it's still reasonable.

As far as money - as long as they are both putting in the hours to contribute to the family, I don't see an issue. If the husband is putting in 60 hour weeks then of course she should pick up the slack at home if she is only working a 40 hour week. However, taking care of small children is more exhausting than most jobs, so there needs to be a balance there as well.

For example, my father was the breadwinner and my mom was a traditional housewife. He still took us kids to the park for a few hours on the weekend so that mom had some time to herself. She needed it when we were small.

The big issue is that many men do not appreciate or acknowledge that their wives or girlfriends provide way more emotional support. This isn't the case in all relationships, but it's true a lot of the time.

Now, in a trad marriage, while the wife may do 90% of the emotional work, she's still happy because the husband provides financial support and he acknowledges and respects what she does for the family. So she isn't exhausted (emotional nurturing is also work) and there is a balanced give and take. Typically in these situations he's "in charge" but she doesn't mind because her needs are also being met.

The problem with many modern marriages - the husband is outraged that she isn't contributing as much financially (though she may have worked to put him through law school or typed his grad school papers for him) while not acknowledging that she's the one doing most of the emotional work. Women will put up with this for a while because they love the guy, then eventually they just get too exhausted or fed up with it and leave. Then the husband is angry or bitter, but typically he gets married again pretty quickly because he needs the emotional support.