Guaranteeing employment by creating bullshit jobs is one of the big mistakes made by the late USSR. Doing so represented a fundamental shift in ideals from the egalitarian "from each according to his ability, to each according to his needs" to the puritanical "the who does not work, neither shall he eat". I keep thinking recently that the US looks more and more like the old jokes about the USSR.
There is no fundamental reason that you need to "keep people busy" with unproductive labor. Due to increases of productivity, we could all be working 20 hour weeks today and enjoying the same standard of living as 50 years ago.