Back in the day, the fma fandom was extremely active on LJ. That's where I made most of my fandom friends and where all the big conversations and stuff were going on, and where the fanfic was. Things really slowed down with the end of the manga, though.

To be fair, though, the original secret was about negative stuff in the fandom, so it makes sense that people would respond to it that way... but I think it also has to do with the fact that for a lot of people, that's probably nearing the end of their experiences in the fandom, so people tend to remember what happened latest, especially if it had something to do with them leaving the fandom.
I had a really good fandom experience overall, but even I find myself with bittersweet memories looking back...