Agreed. Also the insanity defense is rarely successful even when a defendant meets the criteria.
In this case, while I agree Thompson is almost certainly not in good mental health and needs (and deserves) treatment, I think it's also clear that by the current legal standard in the US she's fit to stand trial and receive punishment, including fines and incarceration. Whether the punishment she potentially faces, or whatever she actually ends up receiving, is appropriate and proportional is another question. But unlike some of the people tried for hacking, she appears to have done actual harm.
For the record, I (like many people in the US) think the statutory punishments for many crimes in the US are grossly excessive; that the US incarceration epidemic is one of our great national disgraces; and that "tough on crime" politicians and their cronies are foolish or immoral. But that doesn't mean that people who knowingly do wrong should suffer no consequences simply because they're somewhat emotionally unbalanced. Plenty of other people in that situation don't go around committing crimes.
I'd be interested to know whether she ever sought treatment for her mental-health issues. She apparently has been unemployed for nearly three years (which I'm sure takes its toll), but was often employed since 2005, and presumably would have had health insurance during those periods. Did she take advantage of it? Far too many people don't.