Klepsacovic in his post today recalled an anecdote which was originally related by some Blizzard employee about how during development, WoW [being initially modelled after Everquest] only had questing in certain areas of the game, but when feedback indicated that players didn't know what to do once the quests ran out, the devs had the entire game filled with quests. I also remember that anecdote. It's the kind of thing that sticks in your mind as a "beginning of the end" moment.
Actually this reminds me of that head honcho Pathfinder MMO guy saying recently on their forums [in response to the usual whining] that their game is not about giving players what they want. That guy fucking gets it. MMOs are about stopping the players from doing what they want, forcing them to find world-appropriate solutions. Hence, the world itself is the game and you don't need silly quests to keep you occupied.
I'm not against the existence of quests completely. A great storyline told well can make a game much more meaningful, and some of the epic journeys WoW sends the player on are really something special. But I have to assume that a team of quest developers have only so much creative juice collectively, and this insistence they seem to have on shoehorning a story into every "got to location z and kill y number of creature x" quest is a massive waste of resources at best, and tends to lowers the overall quality of the story experience significantly when you're bombarded with a bunch of crap in between the stories you may actually care about.
I might even go so far as to say that constant quests are antithetical to the core idea of an MMO, railroading players in a genre whose main strength is freeform exploration and discovery. Not to mention role-play-- I'm here to play my character in the game, but they assume that I want to be told what to do and even what my character's motivation is for doing it.
Oh, I just thought of an awesome analogy. Quests in MMOs are like training wheels on a bike; great for those who need them, but as experience grows will only become constrictive and unnecessary. Even those epic journeys I mention earlier could technically be done without any structured quests. If anything this would only be a more immersive experience, the "downside" being it would require the player to remember where they were going and why at each step of the way.
As far as WoW quests are concerned, I'd be content if they would just give us some kind of indicator whether a given storyline is worth paying attention to or whether to just follow the map markers and kill things; whether the fact that the city is being attacked by creature x is a cop-out busy-work quest, or the subtle beginnings of some sinister plot from the x queen who has infiltrated our leadership and is using the war on x as a distraction while she engineers the destruction of Azeroth.