Haven't looked at this closely, but I would think corrections officers would care about keeping their jobs and increasing their pay, and perhaps reducing their work (by lowering the prisoner/officer ratio).

Those incentives seem benign compared to a private corporation, which would be incentivized to increase the prisoner population (build more prisons, more revenue), and increase the prisoner/officer ratio (more profits). These changes would have a negative impact on prisoners, officers, and society at large.