Nothing is risk free. Life isn't risk free. Pensions are certainly not risk free. It sucks, but tell that to the people who worked for Enron and lost all their retirement money when that fell apart.
That's certainly one argument. But on the other hand people who work for State and Local government (usually anyway) take anywhere from 20 - 40% less pay, depending on where they work and the job they're doing, than those doing comparable work in the private sector. In a few positions the disparity can be even greater, such as a public defender vs. a defense attorney in private practice.
Oh, I know there are the exceptions and horror stories, but for the most part those benefits are to make up for the lower salaries. Who would take some of these positions without some sort of equalizer? Competent professionals? And more to the point, is it their fault the States misjudged their returns?
I'm not completely unsympathetic, but there are two sides to the story here.