Private prisons house a tiny fraction of US inmates, an estimated 8% in 2015[0] and the federal numbers are exclusively for the detention of foreigners illegally in the country.
should you construct an argument only by its premise, or should you try to reach the person? I think [s]he assumed that you are not a prison abolitionist and tried to find an argument that might sway you.
There was no prior mention of the person being a prison abolitionist. There was mention of concern about private prisons. I don't know how I am to intuit what a person is truly concerned about vs. what they state they are concerned about.
[0]: http://www.pewresearch.org/fact-tank/2017/04/11/u-s-private-...