Look at the fiasco with the Eclipse 500
I am sure the Eclipse will be EASA's "favourite FAA fiasco" for good many years.
It will be GA's favourite example of how to successfully rip off a lot of deposit holders (IMHO, mostly people with money but who did not understand enough about GA tech stuff to weigh up the risks) for many years, or so I hope. I think anybody who has been in business for many years, honestly and carefully looking after his customers, will see it similarly.
But it would be stupid to use the Eclipse fiasco to declare FAA STCs as bogus - something that EASA is effectively doing as a default position. The vast majority of FAA STCs, or anybody else's approvals for that matter, concern totally mundane items which need an "approval" due to ICAO rules and little else.