Hmm, that could be an attempt at bonding over a common enemy? Kind of like talk bad about the boss behind his back, so that you bond woth your peers? Generally not for everyone, but could see how people get fixated on it if it works for them. Or maybe they are just caught up in the negative media and it has a big effect on their overall mood. Do the happier countries you mentioned have less reliance on media? Again, negative generates views, thats why the news is usually mostly bad.