As I said in an above post: most other types feel *way* more comfortable plowing forward when they catch a whiff of unbalanced power dynamics- I think that INFJs are exceptionally sensitive to it whilst having the least amount confidence that we know we’re Right about the gut feelings we get. I think that probably more doorslams than not are because the INFJ has a gut feeling they can’t get rid of, whilst being totally and completely unsure about whether it really is the other person or if it’s them- and (we're so absolutely and completely bombarded with Ni possibilities that) figuring out where and how to draw a boundary starts looking like one of Gödel's theorems.
INFPs have an advantage in that they seem to inherently feel an importance of their personal viewpoint that we struggle to justify. On the downside, it can make them sound "me me me"- but on the plus side, they are ABLE to say "me me me" in a pinch, when backed into that corner where it becomes necessary; when INFJs get backed into that corner......*crickets and tumbleweeds*. And while I think a great many INFPs are too humble to actually say "me me me" lightly, my point is rather that they have more access to it than we do in the first place.
I think that INFJs don't want to say anything until they are relatively certain (1) they aren't being controlling (many have expressed loathing about forcing their ideals onto other people) and that the need they are to assert is completely reasonable and (2) the person in question would prefer they assert that need rather than simply back away and disappear. [It's rather ironic- people who show up and say that backing away/"doorslamming" is a form of "controlling" are inadvertently locking in any suspicion they are indeed 'incompatible'. I think it appears outwardly as some need to control the external environment, but it's more like a need to be able to know what to expect in the external environment because it's so entirely taxing to have our focus dragged out there (least Se). The more someone else needs to perceive this as 'control'- they more I feel the need to distance them because they clearly see the world so absolutely differently from me that perceptions are likely irreconcilable.]
eta: Actually- I think this is something totally germaine to the discussion- if someone around me expresses the opinion that they think I'm "controlling", I am absolutely going to back away from them......not because it's unflattering, but because I'm not interested in "controlling" anyone. The notion that I'm backing away because it's not flattering is.....a very petty assumption to me. It presumes I could change if I wanted to- and that I'm simply dismissing the opinion because I don't want to believe it. On the contrary, it's because I believe that's their experience- and if the best I can do at being malleable is still coming across as 'controlling', then that person is incompatible with me because I have no interest in making someone feel controlled.
I think that- because J types tend to have a more forceful tone- Ps project *a lot* of certainty into what we're saying that truly isn't there. I suspect many Ps are so certain of their perception of it that they don't believe it's projected- it maybe seems like there's no way someone can have that tone and not be certain.....but I believe the reason most INFJs back away from acquaintanceships is because there's so much uncertainty surfacing about the interpersonal dynamics with someone that it gets overwhelming. There's this "I don't know if it's you or if it's me, but something about this has become more effort than it's worth" element to it, I don't know how else to describe it. I think that everyone experiences that feeling every now and then- but we seem to experience it at the drop of a hat.
I think the reciprocate may be the 'manipulation' and 'playing stupid' it seems like NFPs do- it's really hard to imagine not having access to those parts of my memory that prevent me from even attempting to put forward the kinds of 'raw batter'* that NFPs do. I could either trust it really is their blind spot- even though I can't imagine what that would be like to not remember details that would render what I'm putting forth obsolete- or I can assume they really do remember the details and they're just trying to see if they can get away with it/checking to see if I'm stupid enough to buy what they're saying (which is how it appears).
*eta: Because people have asked, my original 'raw batter' analogy under spoiler: