Earlier quoted context omitted.
Personally, it came from working for a massive union (government, not US) for many years. The downsides are real: hard to fire bad performers, your merits don't matter at all (the guy doing the bare minimum job description gets the same raises as you), wayyy too much focus on seniority (for promotions, vacation selection, etc), and overall just too many rules (for example, "unlimited vacation" works great with my cur…
> hard to fire bad performers Why do you care about this as an employee? You get nothing when somebody else makes the company more money.
More practically, if I'm working at a place where my team has fixed head count I'd rather us have the ability to replace someone who's not contributing to the success of the team.