Why Mandatory Social Security Makes Sense

NO--that is not a picture of the neighborhood in which I live.  However, a few years back I was blessed (read tormented) to serve as president of a neighborhood with 1600 or so homes that did not have a mandatory homeowner's association (HOA).  This neighborhood is very nice but only about half of the homeowners choose to pay the voluntary dues ($300/yr) that pay for common area  maintenance, security patrol and regular events.
$25 per month is not keeping people from joining so what is?    Why would some people voluntarily pay dues AND volunteer their time while other neighbors do neither? Everyone benefits from the maintenance and security service just like all Americans benefit from the financial safety net known as Social Security (SS).

We can speculate about the WHYS for both but I'll go with the Bob Dylan lyric "...you don't need a weatherman to tell which way the wind is blowing."  Let's go with the 50% rule created below for the purposes of this post.  

• 50% of your neighbors would likely not voluntarily join the HOA.
• 90% of Social Security recipients depend upon SS for greater than 50% of their monthly income in retirement.

Even in a highly visual, low cost, immediate feedback situation like the HOA there is only about 50% participation.  With Social Security there is certainty that a person will get older AND need retirement income, however, most people do not save adequately.  Clearly most people rely heavily on SS and choose to spend their money on things besides saving for retirement.  (although not the HOA;-)

According to the Center on Budget and Policy Priorities http://www.cbpp.org/research/social-security/policy-basics-top-ten-facts-about-social-security women, minorities and lower income workers benefit disproportionately and as a result millions of elderly Americans are kept out of poverty.  

I'm not saying there might not be a better way or that I wish people would make better decisions BUT, FOR NOW, it seems the mandatory system is the one that works the best for most people.  

Any ideas on a better way?