Thalidomide. While it is being used today (just not with pregnant women), it is still cited as a drug that was approved (not in the US, though) as being safe, but was not.
My brother the sociopath who lied, stole, and lived off my parents until he died of cirrhosis induced liver cancer. He couldn’t serve as a good example, only as a dire warning.
I’m not a car fanatic myself, but I understand that a lot of folks believe the Edsel to be much maligned, especially the members of the organizations you note. (To my astonishment, there is a Yugo owners club). Although there were mechanical issues (as there would be for any newly-introduced car), the problems with the Edsel were more 1.) The styling (especially that front grille), 2.) the pricing (despite their original intentions, way too expensive for what the car was supposed to be) and 3.) the name.(although “Edsel” is still way better than “Mongoose Civique”).
The Yugo, on the other hand, apparently had pretty significant mechanical issues. It managed to make several “worst car” lists on its own, without help from bad marketing and high expectations.
You might be interested in the book “Disaster in Dearborn”. Although it is mostly about the Edsel, it also gives the history of the Edsel in the larger context of the company politics and business decisions of the 1950’s Ford Motor Company.
It certainly didn’t help that Robert McNamara was fighting against the Edsel. He wanted to create a “super Ford” instead. He is quoted as saying “give me $15 to spend on the Ford”.
And the poet Adrianne Moore’s suggestions such as “Mongoose Civique” are generally held to be tongue-in-cheek suggestions, she liked the SOUND of the words. She also suggested “Utopian Turtletop” and what was more likely “Silver Sword”.
Oh yes, and there was the recession at the end of the 1950’s. Customers found that they could easily move up to a discounted Mercury instead of purchasing an Edsel at the introductory price.
Surprisingly, both of these cars have their fans. Yugo owners will point out that while they break down a lot, they are very simple to repair with just basic tools. So if you know how to work on cars it’s not all that hard to keep a Yugo running. It boils down to expectations: Americans expect a car to not require any attention beyond basic maintenance, while Eastern Europeans at the time considered it normal for a car to need frequent, relatively minor repairs.
Same with the Trabant. Its fans laud its simplicity. I imagine working on a Trabant is not unlike working on a lawnmower.
Pet Rock. Because, haha, gullible idiots will pay good money for anything.
I drove one as part of a guided tour in Berlin. Our group met up at a parking lot where they had about eight cars staged. We took turns driving and followed the guide. He pointed out assorted landmarks and things via walkie talkies. It was super entertaining. The car was a great novelty and super slow but the clutch was one of the easiest I’ve ever used. The gear shift is on the dashboard.