Okay, I see both sides of this issue. Yes, people can be psychologically unhealthy. Probably what people mean when they ascribe the word "unhealthy" to functional use is to reference the state of the individual: depressed, angry, controlling, manic, et al. People are often "unhealthy" when they are hurting. One of the things I despise most is when the word "unhealthy" is thrown around like it is an insult - people are unhealthy because they are sick or wounded. People behave in "unhealthy" ways sometimes because they are hurting inside, have "issues" from their past, or might even suffer from mental illness.
ON THE OTHER HAND...is what some people call "unhealthy" just an ethical view?
I mean, take Vladimir Putin for example: is he using Ni/Te/Fi/Se in an "unhealthy" way...or do we in the Western world just disagree with his ethics? (These are the things that keep me awake at night, lol).
I think that might be what the OP is getting at ...these ethical interpretations of other people's functioning. If your ethics clash, it doesn't mean that the other person is necessarily "unhealthy" now, does it? Or doesn't it?
I hear people with Fe talk about "unhealthy Fi" a bunch. Sometimes I wonder if they just mean they don't like our individualized values (or occasionally lack thereof).
It's all very complex, and we're all a bunch of armchair therapists around here (instead of armchair philosophers) so our estimations are bound to be opinionated and not always correct.