My late father referred to unions as “The Great Society For The Advancement Of Mediocrity.”
But the reason I truly despise unions is because of their inherent anti-American nature.
If the Founders shared one unifying attitude it was the one best described by John Adams - that we should be a nation of laws, not men.
They were fighting against a clubby system in which you got ahead by being an insider and the insiders protected their racket by swindling or threatening outsiders. The rules were ignored, or enforced selectively.
Union hatred of meritocracy and love of mediocrity is all about that clubby, incestuous attitude - of being "connected", of "he's one of ours", of "give me my taste."