Yeah, I saw the comment. I wasn't going to reply to it, but I might as well unpack my reasons why: the ethics of imprisonment are fairly complicated, and depend not only on deterrent effects and the suffering of prisoners but also on a number of secondary effects with their own positive or negative consequences. Resource use, employability effects, social effects on non-prisoners, products of prison labor, et cetera. I don't feel qualified to evaluate all that without quite a lot of research that I currently have little reason to pursue, so I'm going to reserve judgment on the question for now.