In the US sometimes the evidence isn't clear that facilitating "join back to society" is an actual goal (it's often a stated goal). It often doesn't seem to be a policy priority.
It is whether the US is looking at the results achieved by other countries and whether the US is trying to emulate successful strategies.
As a sweeping generalisation, I see that the US says "that doesn't apply to us", always finding some weird excuse. Your invalid response is kind of an example.
It's a fairly common sentiment that the U.S. penal system is heavily skewed toward retribution than reformation.[1] But identifying a problem on the one hand, and quantifying and addressing it on the other, are two entirely separate tasks. The latter is typically much more difficult.[2]
[1] Justice Anton Scalia admitted as much in court, "Well, I thought that modern penology has abandoned that rehabilitation thing, and they--they no longer call prisons reformatories or--or whatever, and punishment is the--is the criterion now. Deserved punishment for crime." Oral argument, Miller v. Alabama, 2012.
[2] Thus the quip, "Everybody complains about the weather, but nobody does anything about it." A reformulation of a Charles Dudley Warner quote, who, interestingly, also seems to have been an advocate for prison reform in his time, among many other civic and political reforms. See https://en.wikipedia.org/wiki/Charles_Dudley_Warner and https://books.google.com/books?id=ktwRAAAAYAAJ&q=+%22little+....
If you look at this recent paper[1] by the lancet on "The psychological impact of quarantine and how to reduce it: rapid review of the evidence" (coincidentally it's about the corona virus) then you might notice that the effects of isolation are exactly what prisons are designed to do[2]. For quarantines it's a huge dilemma ofc.
[1] https://www.thelancet.com/journals/lancet/article/PIIS0140-6...