We don't cook because our parents didn't. Prepackaged convenience foods have always been something of a status item. This whole "return to cooking" is something of an amusing rebellion to me, since it was something of a stigma in my childhood. If your parents had money, your lunch was filled with tasty items sealed in plastic from a factory.

I used to bake bread in my dorm kitchen. My floormates thought it astounding. This is how I learned that nobody's parents had taught them how to cook. As an only child of a single parent, the responsibility for the evening meal fell to me (as well as my own meals throughout the day). Eventually I set upon the family collection of cookbooks and was allowed to make pretty much anything. Even a recipe from a Campbell's Soup cookbook for oatmeal cookies containing a can of tomato soup (as disgusting as it sounds).

Perhaps it's worth noting that my kids generally prefer prepackaged foods over our cooking. So maybe it's a cyclical thing, in some subset of each generation. But I'm hoping that teaching them to cook will change that.