This move is clearly about profits. The money being drained from these prisoners and their families goes to for-profit corporations. Have no doubt that those making the decision to implement this scheme are making profits, both directly and indirectly (Governor Cuomo among others). Kickbacks, campaign contributions, and payoffs (both now and in the future) are just a few of the ways. That's how business is done in New York (and elsewhere, but especially New York).
https://www.nytimes.com/2017/10/04/nyregion/corruption-trial...