The thing that needs to be understood - and some of you may already know this - is that before about the midpoint of the 20th century, gelatin dishes, aspics, etc, were hugely expensive and time-consuming; they were the sort of thing that the upper class had their servants make. And then, along comes post-war prosperity and advancements in food science... the latter giving us "instant" gelatin, modern refrigerators, etc etc. Suddenly, "rich folks" food is within the reach of the burgeoning middle class. It still took a lot of time and effort, relatively speaking, but they could do it (if only to show off to the neighbors)... and so they did, to the point that it permanently changed/damaged the status of such dishes.
And that's how a fancy, "classy" food became synonymous with horrifying suburban kitsch.
Great idea, let the kids eat BALLS OF FROSTING off the tree and then run around the house until they burn off all that sugar.
EDIT:
a friend wrote:
Or throw it up! Festively!
The open-faced hash sammich actually doesn't look too bad (in part because the product - 7up - is more "adjacent", rather than "cleverly" incorporated like too many of these dishes), and the ham dish might not be, depending on what it's topped with. The rest, however...