I think that's overly simplistic, tbh.
When I was young I worked retail and I would be absolutely wrecked after a days work. I can't imagine doing that work at my age now, and then coming home to cook a meal. I think that long hours, particularly at physical work, makes it really difficult to manage proper meals.
It's fine to say that cooking for your kids should be top priority, but the reality is that it can't be a priority over paying the mortgage.
Also, fine to say that cooking is a skill that any parent should have, but where do they learn it? I learned to cook from my mother. I didn't learn it at school, or any where else, so presumably if my mother couldn't cook then I would struggle to do so as well.