Doesn't mean it's okay to kill them, does it?
However, I googled Albert Woodfox, one of the two prisoners in question, and I have to say that, in this case at least, there may be some merit in the "cruel and unusual" comments. His original conviction was for armed robbery, bad enough but not worth a life in prison, much less in solitary. And it MAY be that the conviction for killing the guard was politically motivated, and he MAY not have committed the crime. There is probably justification in reviewing the conviction, and possibly in overturning it. Even the victim's wife doesn't think Woodfox did it, which is pretty unusual.
So yes, in this case, it's possible that the solitary confinement might be wrong. That doesn't mean it would be wrong in every case. The original post didn't specify what kinds of prisoners these were, whether they were relatively well behaved or basically animals in cages. Yes, sometimes criminals really ARE bad people!