You want to know why all of these people suddenly joined the thread? First, if you notice at the bottom of the thread, it will say who's viewing the thread at any given moment, so, yes, a lot of people have been reading and not participating. This has been a popular thread. Second, you need to take a step back and look at what's been happening recently through a longer lens. You're too up-close and personal right now. Look at the general group dynamic information that's available (after you read some of the descriptions in the link, do you see them happening in this thread?)
I'll tell you what I see. I see how Fe controls the group dynamic because that's what Fe is about--group dynamics. From what I understand, Fi, on the other hand, is NOT about the group at all. If you notice, most of the Fi people who have posted in the thread tend to not take sides. Their posts are either trying hard to stay as neutral as possible, or have reluctantly decided to speak to one side or the other, knowing that there are consequences for speaking up that might not align with their personal values. And a few, like PeaceBaby, have taken a firmer stance on what they see. When Fi speaks out, it's about the individual values and has little to do with the group. They aren't wired for group dynamics, but they've had to deal with them all of their lives the best they could. So, you can't see Fi as taking sides, the way Fe naturally does. The ones who have spoken out have most likely been pushed by extreme circumstances, combined with their personal values, to speak out and pick a side.
Fe on the other hand, is all about sides. We categorize. Things are this or that. Black or white. Very few grays. We poll and come to conclusions based on majority or what appears to be majority and try to work towards a smooth running system. What I see happening in the broader scope with Fe posts is that the comfortable norm was challenged. In order to get back to the more harmonious norm, there was some soft pushback. When that didn't work, there was some harder pushback. Once the pushback went beyond a certain point of social acceptance into subtle and outright personal attack, bystanders were pushed into commenting and taking sides, so that a comfortable, smooth running system might be reached again. If you notice, most of the posts that directly take a side are Fe. Those who were uncomfortable with the conflict, but didn't want to participate in it, made fluff or indirect posts to try to diffuse some of the emotion. And a few Fe posters have also tried to bring back a more diplomatic tone in order to move the conversation forward.
Unfortunately, I think change comes with the price of being uncomfortable. Everyone seems to agree that the norm (INFP/INFJ communication) isn't working in some way. It's at an impasse. Slow, steady, diplomatic change is possible, but like rain wearing down a mountain, it might take so much time that it might not be practical. So, perhaps an earthquake is needed in order to bring some of the hidden strata to light and foster change. Not a very pleasant idea, an earthquake. Most people, whether Fe or Fi, won't want to start one because the consequences can be devastating. So, people tend to not speak up against the status quo, even if they don't agree with it. Hopefully, a lesser degree of shaking up will suffice to move what wants to stay in place. But until enough people are uncomfortable enough with the norm to act, the norm is what we'll be stuck with. Because Fe wants a smooth running system, whether that system is optimal or not. And Fi might not like the system they're stuck in, but they don't tend towards organizing into groups, and they have so little power against the group as individuals, that they end up bending or breaking.
Are people doing all of this consciously? No. I don't think so. I think, for the most part, people are reacting out of their unconscious and subconscious and then providing some sort of rationalization in order to explain.
And maybe all of this will also address part of March's post, too: