"From each according to his ability, to each according to his need" - Karl Marx

"He who does not work shall not eat" - Vladimir Lenin

“…people can sustain high levels of cooperation in a public goods game, as long as they have opportunities to target free riders once it becomes clear who is contributing less than the norm...

Everywhere, the contributions to the public good decreased over time…It is likely that contributors decreased their level of cooperation if they observed that others were contributing less than expected and were therefore free riding on them.

It seems as if those people who contributed more than the average liked to punish the low contributors for their unfairness, or for violating a social norm of contributing. Since the payoffs of free riders depend on the total contribution to the public good, the only way to punish free riders in this experiment was to stop contributing. This is the tragedy of the commons.”

- Section 4.7 Public good contributions and peer punishment - The Economy

Working is a way of contributing to the public good, if not by the product of one's labor, then by the taxes one pays. The free rider problem is about what happens to the body politic when individuals able to contribute to the public good choose not to do so, and yet still receive contributions from the labor of others. In game theory simulations, what happens is that those who were contributing stop contributing if that is the only way to punish the free riders.

There are millions of prime-age (24-54) men who are not part of the US labor force. According to The Long-Term Decline in Prime-Age Male Labor Force Participation (an Obama Whitehouse publication), many are unmarried, childless men with limited education and skills, living off other household members and spending much of their time watching TV and socializing. There are also millions of unsuccessful applicants for federal disability benefits: individuals who did not feel they could work but whose applications for benefits were rejected. 

Between prime-age men who have left the labor force and individuals who have signaled their desire not to work by applying for disability benefits, that's over 40 million people alone*.  With a Universal Basic Income (UBI), I suspect most of these individuals would opt to live off the UBI and not work.  There would be a free rider problem.

A substantial free rider problem zaps collective initiative. Knowing that millions are receiving public goods but not contributing to the public coffer would be demoralizing and infuriating to many of those working their butts off. Some would be tempted to slack off. Economic vitality and growth would suffer, along with the financial wherewithal to fund a UBI. We’re talking tragedy of the commons.

I'm not saying, like Lenin, let them starve. Of course we need a safety net.  But good medicine turns poisonous when the dose is too high.

* See Universal Basic Income: Effect on Labor Market Participation, Part II,  Universal Basic Income: Effect on Full-Time Workers, Universal Basic Income: Lessons from Disability Benefit Programs, Part II and Universal Basic Income and Part-Time Workers for details on numbers and other groups likely to opt out of the labor force under a UBI system.