How is forcing one to work any different than slave labor? Even in a capitalist wage system something is gained for work and one can choose to leave their employment, but in this system they cannot.
Only those who are able bodied should be forced to work under these circumstances. There are people that exist who have medical issues that keep them from being able to work.
This will make social benefits even more expensive for everyone. We would have to hire supervisors, bureaucrats, security and more enforcement, etc. as well as provide supplies and a place to work. This would be an incredibly expensive way of gathering unskilled labor, and is government overreach.