Yes Its mandatory, is less effective than the private sector, pays less than what you pay in, and people who pay little to nothing into it often get more than those that pay in their whole lives.
So why can't the poor be expected to learn to budget more wisely? I do! I make low 6 figures as a Piper and live more frugal than those on Govt assistance. I see poor folks with fancy rims and stereo systems in their cars that I MUST compensate for. Nothing should be a guaranteed human right...