An example from Antiquity shows why in principle private enterprise has been historical more humane to its workers than state-run operations.  J. G. Davies, “Condemnation to the Mines: a Neglected Chapter in the History of the Persecutions”, Univ. Birm. Hist. Journal. 6 (1957/8) 104, writes about mines during the Roman period:

The ownership was mainly in the hands of the State, although there were some private concessions, while others were granted to municipalities.  One of the results of this State control was a disregard for the working conditions of the miners.  While the private owner would have to find the money to replace slaves who might die and was therefore concerned not to kill his men by overwork, replacement cost the State nothing since it could merely divert to the mines more prisoners of war or more convicts.  In such a situation, those upon whom this sentence was passed were driven to the limits of their endurance; their lives were cheap and the mortality rate was high.