This all started during WWII, when factories in the US started pumping out processed food for the troops, and women back home had to get… creative with their cooking in order to stretch ingredients. Both of which led Americans to be more open to crimes against food, since they just grew used to it.
So once the 50s came around and housewives had all these expectations put on them about what a good wife is, they had a problem. Convenience food was bigger than ever, and it was really tempting to make something from a box or can instead of spending hours in the kitchen every day. However, there was this idea that a housewife who resorted to convenience food was lazy and didn’t care enough about her family to put real effort into her cooking. The “compromise”, then, was to use processed stuff as a starting point, but then add personal touches to it like improvised ingredients and fancy little garnishes. This kind of mutated into a culture of one-upmanship, where women related their value as wives and their status among their peers to who could be the most Extra with their cooking. This is when all those weird molds and stuff started coming into play.
Meanwhile, companies started coming out with branded cookbooks as a way of advertising their products. So like, you’d get a Jell-O cookbook that would shoehorn that into every possible course, and for products like, say, canned soup, the results were a little out there. But the public didn’t mind, because like I brought up earlier, wartime conditions kind of ruined everyone’s perceptions of what tasted good.
These were the main factors from what I found in my research, but I also remember reading that all these new food products being pumped out, plus refrigeration becoming widely available, meant that people suddenly had a bajillion more options available to them in what kind of stuff they could use to cook. So there was also a lot of “let’s throw stuff at the wall and see what sticks”, just because that was a novel idea, and it’s not like anyone instinctively knew how all these newfangled foods would taste together anyway.
The two main things that brought this era to an end were increased public awareness of nutrition, and feminism. Once it became more widely known how terrible processed food is for you, more and more people started returning to natural ingredients, and dieting became a big thing. This was also when a lot of women were entering the workplace, so they had a lot less time and energy to devote to cooking. So the stigma against zero-effort meals disappeared, and it was finally acceptable to just pop something in the microwave and go.