When people quit smoking, they become, in the words of author David Krogh, "edgy, hostile, depressed, confused. Behold man." [Smoking, The Artificial Passion. 1991, W.H. Freeman and Company.]
The last thing any jailer wants is an irritable incarcerated population. Yet, many jails and prisons have become torture chambers for prisoners. I'm betting that violence increased when the no-smoking policies were implemented.
It's nice to see something sensible done about the situation.