What is the "problem of leisure"? Why is it a problem? When did it arise?

The problem of leisure is that "Americans have too much time on their hands (pg. 16)". This is seen as a problem because with too much extra time, Americans may lose sight of how to spend that free time wisely. This was first noted as a problem in the 1960s when various community groups were seeing a large increase in activity because citizens had more time to actively participate in these groups.