All of this is true but there are companies that were driven out of business due to unrealistic demands from their union. As you pointed out, humans are quite o

All of this is true but there are companies that were driven out of business due to unrealistic demands from their union. As you pointed out, humans are quite often irrational and there's no reason to think that unions will always act in a rational manner that protects workers from losing their job through employer bankruptcies. Certainly, it is the goal to prevent that from happening, but humans being humans, often don't see how a particular short-term goal can end up harming their long-term goals. Of course, most companies, no matter how profitable, will cry poverty to each union request that's going to have costs to the company, so an adversarial relationship builds, with both sides insisting the other is acting in bad faith. Plenty of times, it's true for both sides.