In its own way, it is punitive. It takes care of all of his needs and desires except one; genuine social interaction. Look at the lack of sympathy here and on the post. His personal comfort denies him any social comfort.

Semitic religions describe hell as the absence of God's light. I can imagine the very same from the absence of social.

If your actions are politically motivated, being punished or tortured makes you feel justified. It also makes you a martyr to the cause. A soft beige room and benign guards has got to be pretty aggravating to him. He thinks he should be the next Adolf Hitler and they're like "Oh Anders you're getting a bit worked up, maybe go play some playstation and cool off?"

I don't really care. Punishment will benefit nobody.

It absolutely should be for rehabilitation and not punishment. This guy is clearly beyond any hope of rehabilitation. Just put him down quietly and dump him in a shallow grave, anything else is excessive.