Rosie, it's a bit of a class and a generational thing (as so many things are...)

My family is from New Jersey. My (working-class) mother grew up in the 40s and 50s, when everything was about convenience and minimising housework. As a result, most of her "home cooking" contained processed food. I ate ridiculous amounts of tinned veg as a kid, and the recipe books she favoured contained "ingredients" like tinned soup. Often a recipe was simply a combination of different processed foods from tins and packets, and a "homemade" cake came out of a Betty Crocker box, with the icing out of a pre-prepared tub. She never whipped cream, but there was always a tub of Cool-whip in the freezer.

However, my grandma still cooked and baked properly, so I learned some from her, but largely had to teach myself to cook with fresh ingredients when I got married, and lived in England. I found that, in England, even my mum's generation tended to cook with real, fresh ingredients a lot more.