J Adam G:
Believing that everything and everyone is fucked up is a very common thought/feeling during the Dark Night, though it can arise any time that someone takes a serious look at how people work. Especially if looking with an eye towards the problems of people and societies. You could find similar outlooks in some forms of absurdism or other postmodern or poststructuralist thought.
That said, there are probably just as many sensible ways of looking at the world that don't involve thinking everything is fucked up. Views as just views, rather than necessarily being the truth of how things are, you know?
I think I may be in a position that means that I'm becoming very aware of my own conditioned psychology and therefore able to see similar things in others (and also hypersensitive to it).
It's an experience that has completely killed any interest in politics, but I can see how it might lead someone to do the opposite and become some kind of utopian socialist or something similar.
I'm not sure why your psychotherapist friend thought that "patching people up" wasn't a useful endeavor. If everyone has so many problems, why not try the best that one can to help them? Forgive me for making such a rash assumption, but it seems to me like that decision was based on something like burnout, being a dark-night yogi, or no longer knowing how to enjoy his job. From my understanding, the dukkha can get really bad around third path, or while working on the fourth path but not having gotten arahatship yet. It would be understandable for even a very advanced practitioner to take on such a pessimistic view.
I couldn't imagine any other reason for a psychotherapist to believe that people can't really be made significantly better in the face of so much evidence to the contrary. I, for one, was near-suicidal for about a year back in high school but I've come a long long long way since then, to the point where my experience is vastly dominated by pleasant and neutral sensation rather than unpleasant. So I would respectfully disagree with the conclusion/excuse that your friend had, assuming I wasn't in something like Reobservation with its unending dukkha. If I were in Reobservation, I'd probably be jumping the gun to agree with him... That's how views are, I guess.
This is just conjecture, but I think the time he decided this he had been starting to practice mahamudra (maybe a year or so into it). It might well have been a consequence of some realisation from that. As far as I know he moved from being a part time therapist to being a nurse - a deliberate decision about where he would be the most use. If I remember correctly, he was of the opinion that only practice could help others in any permanent manner.
This kind of reminds me of the tale about Avalokiteshvara becoming despondent about helping others, causing him to contemplate breaking his vow to help others and resulting in his head exploding. Maybe this experience is what the myth is pointing to.