I mean that’s the whole point of the insanity plea. He didn’t do it for greed or for evil. He had a severe chemical imbalance that they’ve been able to treat and now he is once more socially viable.
60 years of prison would be to punish somebody for doing something that they knew was wrong, or depending on your world views to make sure that he stays incarcerated for public safety.
They didn’t give him 60 years in the funny farm to make him think about what he did. That’s the maximum amount of time he was supposed to spend in there if he didn’t get it sorted out.
That said, he would be kind of nice if we had a public health system that could check up on this guy once every 30 60 days or so, Make sure he doesn’t fall off the wagon on his medication.