Indeed, according to the conference call bullet points, casual players aren't being engaged enough, and I think a lot of it really is the emphasis on solo play this expansion, including LFR. Few friendships are forged in a LFR environment, whereas you might make a friend or two in a normal mode pug. Communication is pretty much optional.
Many of my guildies over the years said they kept playing for the people/social aspect. With WoW's huge playerbase that was one of the main draws. Now that server transfers are killing off a lot of servers and we're spending time doing pet battles, dailies, and LFR, there's not enough social activity going on. Blizz probably realizes that and they're going to try to get players back into normal somehow or do that 'beer league' idea at least.
Time will tell.