I sometimes (cough) complain about GW2, but I have to admit that making an MMO is no easy task. MMO players devour content at an amazing rate.
Also, wikis inside two weeks? You know Dulfy gets pre-release info for/access to content in multiple MMOs, and most of the rest just copy off her, right? And, worse, developers are happy to give it to her.
I guess the conclusion I would draw here is that through our own desire to be lazy and have things handed to us, we've ensured that the current generation of MMOs are unable to even maintain our interest. People on both sides of the spectrum, players and developers alike, seem equally inclined to embrace and continue on with the status quo.
I kid, but I'm sure we've all noticed the same trend, and you're spot on in your analysis. The issue is definitely multi-faceted. To elaborate on what I was saying above in my earlier post, the act of sitting at the computer and logging into and playing an MMO usually involves you sitting alone in a room. It's a hurdle developers should be aiming to overcome when designing MMOs, but they've fallen into the trap of believing that they'll generate more revenue by taking a two-step approach of designing much of the game for solo questing, while slapping on some group-only content here and there; perhaps that's just a logical outcome of the casual v. hardcore debate.
Think of some of the great titles in MMO history, and how many of them absolutely required group game play, often for some relatively mundane stuff. Add in the growth of 3rd party voice chat, social media, and the proliferation of solo-friendly mechanics (ie companions/minions), and top if off with developers who just don't seem cognizant that you need to literally force people to interact, and it's no surprise that gaming has grown to be such a lonely experience.
Here in GW2, there was one example I can think of immediately which demonstrates this; and it relates to downtime in group content, something that may just be on some developer's list of anti-fun mechanics. Sorrow's Embrace path 1 (IIRC) had a series of thirteen or so minion patrols which you would either need to wait for them all to pass and despawn, or try to fight and usually wipe often on. Waiting for the patrols to pass was the most social activity I encountered in this game, discounting any voice-chat based guild socializing I participated in. And then ANet went and changed it; how I don't remember, but even as lame as that design was, it was better than pushing us through the dungeon a few extra minutes faster.