If we had a free enterprise economy, then their fears would be baseless. As long as a person is able to work and willing to accept a wage commensurate with his productivity, there will be an entrepreneur willing to hire him. In our interventionist economy, government regulations make it tougher for workers. Entrepreneurs have their capital taxed away, their ability to hire constrained by rules and regulations, costs of employing mandated by the state, and so on.
When the G.I.s came home from World War Two, entrepreneurs started new businesses and expanded old ones to employ over 10 million ex-soldiers in a matter of several months.
Generally, labor is the most adaptable resource to changes in use. Unskilled workers can move into and out of a multitude of different activities and still be productive and therefore, find a job and earn a wage. Capital goods are not so easily moved from one task to another and may experience under-utilization, or even obsolescence, more readily.