One commonly held notion is that the university tenure system is instituted mainly to protect those in the social sciences who are critical of the current establishment or hold controversial views. This is of course highly valuable for a free society. Recently there has been some suggestion that tenure should be disbanded in the sciences and be replaced with 5 or 10 year renewable contracts. The main reason for this argument is that every department has unproductive faculty and there is no way to replace them.
However, it could be argued that academic freedom is just as important for the sciences. Faculty need the ability to pursue risky ideas that may have no return. If Andrew Wiles was on a five year contract, he may never have had the peace of mind to hole away in an attic for seven years to prove Fermat's Last Theorem. Progress is not possible without failure. The tenure process should be decided carefully but once conferred, not producing another piece of research for the rest of one's career must be considered to be an acceptable outcome.
The argument could be expanded for justifying unemployment as an acceptable career choice. A just and free society should provide a minimal standard of living for all citizens. There are both practical and moral reasons for this stance. Even in our current society, people do accept that some people either through misfortune or bad judgment fall through the cracks and need temporary help to get back on their feet. One could also argue, although I bet this gets less support, that welfare could serve as a stipend for segments of the society wishing to pursue interests in areas that have no current commercial value such as writing a novel or painting. This is akin to academic freedom on the society scale.
But the most compelling argument is a moral one. A person born into a structured society does not have the freedom to live in their natural state. They must follow the conventions imposed upon them. They have no choice to opt out. They cannot choose to become a hunter-gatherer. In fact, few of us have absolute choice over what we do to support ourselves. We have some choice in the area we are trained but the market ultimately decides where we are hired. Thus, one could argue that compensation for eliminating this freedom could be a welfare system. Now, obviously, if everyone chose to take welfare the system would collapse. So to make it viable, any form of work should have a higher compensation than welfare. Did I hear someone say minimum wage?