I totally agree with that, meanwhile I think mnky meant that illness doesn’t necessarily remove all your judgement. You can have totally coherent thinking on a field while being incapable to reason on another. Easy exemple : Math and Empathy, where schizophrenic may excel in the former while lacking the later. Someone affected by trisomy 21 have more chances to get the opposite. <- generalization for illustration purpose, those affections are complex and schizophrenia is a spectrum anyway.

Even for non-Ill-defined, PTS and other trauma or just learnings- can do that to anyone and age doesn’t help to escape the reasoning-habits. Wise are those that can stay free from mental cages.

Paranoid delusions related to obsessive compulsive disorders or personality disorders stemming from post traumatic stress rarely seem to qualify insanity pleas except in episodes of law and order even though they can motivate highly irrational and self destructive behaviour.

Does it really count if the difference is "be removed from society for a while by being sent to prison" vs "be removed from society indefinitely by being sent to inpatient lockup"?