SS is only a small portion of the overall budget, but even if it did take up a substantially larger pie chart slice it's money well spent.
I can't think of a better way to pay back all the hard workers who made this country what it is today than to ensure financial security during their golden years. The American worker made this country and I think deserve a well earned retirement dividend.
Another way to look at it is the following. All workers have the appropriate monetary deduction from each paycheck, so in essence, when they retire their just getting back what they already paid into the system in previous years.