About 25 years ago in California, Orange Country went bankrupt and public employees had to do "give backs" of (if I remember correctly) about 1/2 of their retirement funds and other concessions. I think that this will be the model for the future, but a state levels. It may not seem fair to change the rules on public employees, but effectively the rules have changed for private employees because the economy at federal…
You're right: voiding other people's contracts because they (collectively) negotiated better deals than you did doesn't seem fair at all. Arnold knows exactly how to push your buttons.
You're forgetting that govt is a monopoly. GM can promise anything it wants to its retirees, but if its customers decide to buy Toyota, GM won't honor those promises (unless the govt bails them out).
If San Jose makes promises, folks who had nothing to do with those promises are forced to make good.
That's why public employees and public works projects (SJ Arena, light rail, pro-sports facilities) should be on a pay-as-you go or collateral basis. That way, the stadium failure won't be a burden on future tax payers.
If you think that such things are a great idea, buy the bonds. If you're correct, great. If you're wrong, you get to foreclose.