i dunno if anyone really enjoys drawing out silence, or that it's done to be cool. i think usually it happens - and this is mostly based off what i've seen with my extensive family and friends - when someone is trying to prevent something from happening. fear. they got hurt once and don't want to risk getting hurt again.
i don't think most of us are trying to pin INFJs down as doorslammers; i think the point is that it's a popular Fe-based defensive technique, just as lashing out is a popular Fi-based defensive technique. i don't really want my type to be seen as explosive and hurtful, but doubtless it happens. i personally actually used the "silent treatment" every once in a while when i was a teenager - and if someone didn't know how to approach me in a comforting way, then i was very likely to continue the silence. and my Fe-dom mom will sometimes yell loud and clear, too. i don't feel like the rules we're talking about are hard-and-fast... they're just correlations. associated patterns of behavior. and as far as i've seen, with my family and friends, the average response of a Fi user when confronted with a raging attack against them is to rage back. the average response of a Fe user is to leave.
and also, i think sometimes the problem is that the Fe user is trying to reach out in a way the Fi user doesn't understand, and vice versa. if someone's attempt at reaching out sounds more like a continued attack to the other person, then we all may preserve our silence... i know that personally, after i've lashed out all the way, i'm such a huge messed up wreck of emotion that unless they are around to comfort me, i don't want to see
anyone.
i guess my point is, we all attack and block out to some extent. and i'm with you about stagnation. can't stand it.