My dad was involved in trying to unionize engineers at GE, a long time ago. There was a vote, but it didn't quite make it. It wasn't until like a quarter century after he died that I realized he might not have retired early by choice.
I have zero details on it, all I know is that it was pre-Jack Welch, and probably the majority of the engineers felt that they were too good for a union.
I am a member of a union that has a long and convoluted history, but I think the origin was basically about how office workers didn't want to belong to the same union as everyone else.
People said this was folly, that it was splitting the power of the employees to our detriment.