Right there with you.
Only time I’ve ever encountered anything remotely like this is the time my great aunt brought jello to a family dinner and it had grated cheese on top. I did not eat any.
Jellied beef tongue…jellied ham hocks…jellied herring…salmon aspic…tuna aspic…these are fine eating. The fruit-flavored rubber, especially with canned froot entombed in it, is an abomination. The not found in nature colors are especially disquieting.
Check THIS out! Weight Watchers recipe cards, circa 1974
I haven’t read this in a while, so some of the comments may be NSFW.
I actually have a set of those, too. My mom bought them back when she first started WW and they sat, unused as far as I can tell, in the kitchen cupboard until we cleaned out the house after Mom passed away. They’re now sitting on the bookshelf in our bedroom because I can’t bear the thought of someday being in a position to exploit the kitsch and realizing that I threw them away a decade before.
The recipe for spiced cherry relish on that same page actually looks pretty good.
On a related note, I once picked up some seafood custard at the Chinese market. It was memorably one of the worst things I ever ate in my long history of buying bizarre foods at ethnic markets and eating them. So gelatinous and cold and fishy.
http://www.candyboots.com/wwcards/salmonmousse.html
Oh heavens to betsy, you take a fish, mousse it, then form the mousse into the shape of a fish? What is this I don’t even…
It’s like goyfilte fish…
Oh lordy, my grandmother would make these jello things. Jello is too sweet for savory foods IMO. However, this brought to mind the most horrible Jello dish of all:
In the entry on Jello:
One could say also that those Jello paintings could be coming from an ancestor of J.J. Abrams. 
You also needed a refrigerator to do it, so it was “fancy” and a way to show off when not everybody had one.
Fruit flavored and those types of sweet gelatins, perhaps. But a traditional aspic did not require any special powdered gelatin or anything like that. You just throw in enough bones into your stock and it will gelatinize. When my mother makes aspic, it’s just pork hocks/feet that provide all the necessary gelatin. Meat jelly/aspic recipes go back hundreds of years.
Peter Cooper invented powdered gelatin in 1845 but never did much with it as far as sales; he sold the patent to a cough syrup maker who mixed it with fruit flavor and named it Jell-o … who sold it to a neighbor of his, Frank Woodward, in 1899. It was Woodward who made a go of the business.
So since there was at least 50-70 years of availability, sort of makes the whole “it was a new thing and they went crazy with it” not terribly good as an explanation for hideous Jell-o concoctions in the mid-late 60s . I do think as some other people said that gelatin was considered “fancy” a long time after the reasons it was considered fancy and unusual became obsolete.
That stuff is quite popular where I live (Eastern Europe) so yeah, people did and continue to eat it. 
Ah, the travails of being both old and ironically hip! My daughters threw out a few of my old laptops while I was in the hospital. I saw them getting rained on and had to remind myself that two of them were broken and the third might as well have been, though it was cool to use back when I used it around college students. At least I still have my Tandy Model 100, age of 30.
Sweetened gelatine with meat and vegetables in it? Really?
While both fish-in-aspic and fruit-in-sweet-gelatin are popular slavic dishes – my Russian cookbook has a lovely “muscovite” gelatin made with fresh squeezed orange juice and about a billion packets of gelatin, so it’s solid at room temperature – I was under the impression that combining large quantities of sugar and processed meat in one wobbly tower of horror was an American thing.
I believe we’re talking about the general category of “aspic,” (although there appears to be a side discussion with fruit jellos and meat) which is what is in the OP. I don’t see any call for sweetened gelatin products in the OP’s links, unless “Davis Gelantine” is sweetened. I’m assuming it’s just bog standard gelatin.
Ah, the OP asked about Jell-o, and Jell-o is a sweetened gealtin product.
Sure, but “jello” is also used in a general sense by many to describe any gelatin product.
True, but often by those who don’t know anything else. Unsweetened unflavored gelatin will look like Jello and if Jello is all you’ve ever seen, you’ll assume that’s what it is. Which would certainly raise my eyebrow. (“Sweetened fruit-flavored jello spiked with tuna fish? YUCK!”)
But if it the recipe starts with something like Knox unsweetened, or better yet just the natural collagen of the meat/cartilage/bones/etc, the flavor will pretty much be whatever is IN the gelatin. And that can be awesome. Bacon in ham aspic, anyone?
Well, I wouldn’t say that. Colloquially, I am far more likely to hear aspic (or even overcooked fall-off-the-bone “barbecue” ribs) described as “meat jello” than “meat gelatin” or anything that precise. Heck, I know the difference, but I describe aspic as “meat jello” to people unfamiliar with it.