Luckily Norwegians do understand and respect their justice system better than people like you and don't want to introduce such a shitty tool of vengeance just for one guy. Especially since that very fucker wanted Norway to get a much harsher justice system in the first place. Them granting him the same rights every other prisoner in Norway has is winning against his ideology of hatred.
And the success of their justice system, especially when compared to countries who use death penalty and other punitive measures such as state sanctioned rape, speaks for itself. Many countries could learn a lot from Norway.