Pensions are funded. There is a national pension insurance fund. They are completely sustainable, as long as they are funded. A pension is an annuity. The pension money comes from money that is withheld from wages.
Now, if some company engages in wage theft (raids its pension fund), that's fraud just as any Madoff-esque pyramid scheme.
Which pension system are you referring to? State, counties and cities each have their own system. The press tends to lump them all together but they are independent of each other, save for the management organization.
The HN crowd will never believe this, because it runs contrary to the beliefs of libertarianism and the what-I-vaguely-remember-from-Econ-101 crowd, but correctly-funded public pensions are completely sustainable. The main reason is that public pensions operate on a nearly infinite time horizon, unlike a worker's 401(k).
Please don't make generalizations like this, especially of a community you choose to participate in. Your comment reads perfectly well if you omit everything up through but.
Long ago, conservatives believed that public assistance made people immoral. Then Ronald Reagan discovered that his own followers actually like their public assistance when it benefits them and not those "other" people. So conservatives changed their tune and began claiming that public assistance is "unsustainable."
Now, if some company engages in wage theft (raids its pension fund), that's fraud just as any Madoff-esque pyramid scheme.