I got into some ugly argument right on the very first try at participating in a discussion on the site, wasn't really impressed by how the mods handled it (although the one I PM'd was actually quite okay), and never really gave it another try.
I always felt like I'm really missing out and this was probably all just bad luck and a bad combination of personalities in this specific comment thread, but whenever I went back to the site those memories kind of killed the fun for me and I never commented again.
sigh