I feel like this is avoiding the real reason people don't cook as much any more. In the old days, most homes were single income with a stay at home parent. The stay at home parent had literally the whole day to do things like childcare, walk the dogs, cook, and clean.

Today is different. Most homes are dual income. This has the effect of making it so that, instead of having a dedicated house keeper, both people have to be skilled employees for most of their week, until they come home and are told that they have even more work to do. My girlfriend and I, for example, go to sleep at around midnight, and get home from work at about 7:30pm. We have lots of nights where we just make a frozen pizza, and our bank accounts are happy for it.