The psychiatric profession is not without flaws and there are legitimate issues with overprescription of antidepressants, anxiety meds, etc. that may or may not work....
But a lot of people have bought the whole Scientologist “psychiatry is the root of all evil, all psychiatric meds make things worse” perspective.
There’s also general misundestanding of schizophrenia as you note and, that it is obvious that in general medications help most schizophrenics greatly.
You have to live with organic mental illness to know how absurd this is. Yeah crazy people take medications because they are..crazy. However, the craziness came before the meds! And sometimes it takes a lot of tweaking to find the right meds and they control but not cure the illness, and sometimes the patient doesn't take them or abuses them or self medicates to try to feel.... normal..or something else..... and sometimes there is a bad reaction to the drug and it backfires as sadly happened to some I knew. The attempt at treatment fails. This guy sounds like he was deconstructing and seeking to use his flawed brilliance to become more "powerful" as he assumed a fantasy character persona. That does suggest drug abuse. He could have induced his own psychosis by self medicating on something she prescribed or something he cooked up himself in the lab. It happens.
I believe the courts were trying to order Jared Loughner to take his meds so he was sane enough to be tried