When I was younger, I used to be very conscious of my social inadequacy. I still am, but back in the days my way to solve that inadequacy was trying to become something I perceived to be "socially acceptable". I tried to be more extroverted, more interpersonal and stuff like that, which I am not. I pictured in my head that what kind of a person is socially acceptable and tried to become that. Being deep down socially inadequent, that didn't work out very well. Like you said, perhaps the communication, despite the outer eagerness, lacked warmth and genuine interest.

I can kind of imagine that I might have seem like your INFJ acquaintance. It was about me being socially helpless, and nevertheless wanting to be with people. Perhaps I felt like if I'm genuinely myself in a social situation, it's way too eccentric for the most. Knowing that it's hard for me to form relationships, I was afraid of losing the last bits of my social skills. So I wanted to have at least some human connection - and thus, when interacting socially, I became something I'm not.

It makes me cringe a little bit but oh well. Now I understand better, and that's the only thing that matters. It doesn't matter where you come from but where you're going and so on. Social situations still aren't easy for me but I try to suck it up. I'm eccentric but I'm (mostly) done with the changing myself part. It's better to let things go with their own pace. I'm not so obsessed with having human connection either. I no longer think so roughly, as in I'd lose my social skills if I didn't make any human connection. It's not like that. Not that deterministic and absolute.

Nowadays, I have a whole different view on social relationships. Which includes that, nothing else matters but that the two or more people just like each other's company. Everything else is secondary, for example the perceived state of your "social skills" is utterly meaningless. Or, better, the meaning of them is determined only inside the relationship. The state of your social skills matters just as much as they affect the relationship, but you can't know the "effect-value" beforehand. In relationships, things hold no bigger, pre-existing meanings than what kind of meanings they take along the way. This is getting too philosophical, I've got to stop.

I wrote this so that maybe you can understand your INFJ acquaintance better. Maybe they're going through something similar? Though, I don't know to what extent my life experiences can be generalized... probably not very far :P