The hesitation to say publicly what all rational psychologists will privately say — Trump's sociopathy is off the charts — has little to do with medical ethics at this point. Like the hesitation to hold him legally accountable, it's about privilege.
I think the “mental illness” framing is irrelevant to Trump, because he’s rich enough to be functional. So I’d freely say *his sociopathic behaviour is off the charts* but (like Lee) I’d stop short of calling him a “sociopath”. Yes, should be possible to openly criticize behaviour without diagnosis.
The kind of people subject to unwilling diagnosis are often poor or incarcerated. The formal ceremony of directly examining a patient is something Trump can avoid (hopefully not forever), but c'mon. Psychologists have more information about him than they do 99% of patients they examine.