Earlier quoted context omitted.
It's archaic and should be changed, but the way the system works in the U.S. is pretty well known to its citizens, which makes it at least partially the fault of the pensioners. I live in Chicago and every retired schoolteacher and police officer I meet knows full well that they're making an exceptional amount of money in retirement. It's usually part of why they took the job.
IMO, it's no more the pensioners' fault than any other voter. If they're a resident eligible to vote, it's partly their fault. It's not their fault for accepting a job offer with certain terms broadly available.
(1) Pension decisions play out potentially over ~30-40 years.
(2) If we accept that the cause is some official made a bad decision, it is almost certain that pension issues will be ongoing. There is potentially a 40 year window for idiots to get in and screw the whole system up.
So in a sense, some large group of people need to be responsible. Not because it is fair, but because if that isn't how we treat the situation it isn't likely to get fixed for the next round of pension crises. The pensioners were most invested in the success of the enterprise. They are most responsible for its failure.
This isn't a nice position to hold, but the alternatives are a very nebulous concepts of blame and lumping the cost of fixing all the mistakes on the one group of people who we know weren't responsible - people who are currently entering or in the workforce and can pay taxes.