Union rules change all the time. Management just isn't usually willing to offer sufficient incentive during negotiations, since that would eat in to their profits.
You want everything as cheap as possible, which means you want everyone else to not belong to a union. But you want to be paid as much as possible, so you want to belong to a union. Your economic self-interest would be maximized if you were the only unionized person on Earth... but of course that's impossible.
It's not just "corporate greed." I mean that definitely exists and many executives are over-compensated, but compared to other costs like capital, labor, and taxes, that's usually just not that big of a cost center for a large company. That's part of how they get away with it. If CXOs were a significant cost center the shareholders would be less tolerant of those fat compensation packages.
A popular assertion, but one which ignores the demonstrable willingness of people to pay more at places like farmer's markets or shop at stores that don't always offer the lowest prices or widest selection. Since many people willingly make sacrifices on either price or convenience, you're arguing from a flawed premise.
Cheap should be defined in a way that is inclusive of all the costs, both monetary and non-monetary societal costs. Then I think everyone does want everything cheap - this is just a statement that nobody likes waste.
But it's just word games. It would be better if we did away with these pernicious generalizations.