That's quite an unfair argument... it's not binary, either living on the streets or getting social security.
Personally, I don't think the government should be involved in your financial life at all, especially retirement. IRA's should be available to anyone, and maybe even required. The difference is you are in charge of your retirement, not politicians and their political objectives at the moment you just so happen to retire. Why would you want to trust the government with your financial future?
But, that's not to say some system run by the government can't work... it just says social security as was implemented doesn't work. We know it doesn't work because it requires printing money or raising the burden on today's youth unfairly. It doesn't work because the amount of money you put into the system doesn't equal what you will get out, and it doesn't grow with the markets or inflation. Few people can actually retire on social security because it pays so very little.
Any way you slice it... it's really, really tough to objectively call social security "wildly successful", which was the original contested assertion.