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."
