Because that's what unions do. If you were a union leader you'd have to deliver more pay and benefits to your union members every so often in order to stay in your cushy job. They are doing exactly what they are supposed to be doing: Getting more for their members. The problem is that, taken to the limit, this eventually kills the goose.
> Why didn't management just make all employees joint owners of the company?
In what virtually reality does one go from "employee" to actually being entitled to own a piece of a company? These kinds of ideas come from people who've never started or run a business. I've done it several times. If an employee is willing to make the investment, lay it all on the line, take the risks, make the commitment, responsibility, stress and place their own family's and children's very livelihood and future on the line as well as accept all else that comes with launching, running and growing a real business, well, then they are investors and partners, not employees. I have taken trips to the hospital due to the stress caused by business issues. None of my employees ever missed a paycheck or had to worry about where payroll money would come from. Every.
What nonsense.