“Sounds more like a stupidity thing than unionism per se.”
Let’s put it another way. If there was no union, there would have been no strike, and 18,000 people (probably more, if no union) would still have a job today.
NOTHING good comes of unions, whether it’s stupidity or outright evil. In this case, it may have been some of both.
Basically the 1950's model baked goods producers and marketers are all going under ~ unless they change.