I don't know much about this (and this whole thread is a bit confusing when it comes to my perceptions of INFs! I certainly don't come across as polished, and only grudgingly wear make-up, hah...) but could this be an INFJ thing: caring about relevance or getting to the point?
As an example: A while back, my friend blogged something in response to someone else that seemed to be... just completely irrelevant. It was a good post, but she seemed to be disagreeing where there was no actual conflict and responding to perceived arguments that the OP actually wasn't making. The OP was saying X and she was saying Y... but Y was perfectly compatible with X, and the OP would have probably agreed with it; they were just focusing on a different angle of the issue. I replied with a carefully worded post emphasizing that yes, friend, what you said is true and actually really well-said; I agree... but come on, why did you say it in response to the OP? Don't get me wrong; I don't dislike irrelevance in every situation, but when the irrelevant statements are needlessly confrontational, then they seem pointless.
Am I completely making this up? Would an INFP care about this? Just a thought, though.