They claim it's 100% societies fault. So even while trying to defend they remove all agency from this guy. Yes, let's work to improve systems to give everyone a better shake, but don't discard his own horrible actions.
He is morally innocent though which is the point, even if he's criminally guilty. The strawman is hearing "we can't be surprised and we can still feel bad for him" and equating that to saying "he should be let go!". He can still be guilty for his actions even though it's almost entirely society's fault.
No he's not, because once again the vast majority of people who have bad childhoods and mental challenges don;t go murdering people. He is in no way morally innocent.
Post itself suggests its somehow excusable I disagree.
To me makes sense to stea money but to kill other just for sake of killing them is closer to serial killer thinking than desperation .
I think @ParsnipWitch@feddit.de want to say that those murdered people were thought by the killer to be at fault for killer's problems they had nothing to do with.