You call Guild Wars 2's leveling system a series of menial tasks, but I just cannot in good faith agree with that. I happened to enjoy quite a lot the fact that in Guild Wars 2 I obtained experience by doing whatever I wanted. Exploring the world, doing WvW, crafting, completing dungeons. Progressing my engineer to 80 back in August 2012 was the most fun I've ever had leveling in any MMO previously. I drove back the centaurs out of Queensdale and chased them back into the edges of the Harathi Hinterlands. I cleared bandits out of Kessex Hills and protected the roads on the way to Lion's Arch. I helped the Lionguard defeat the pirates occupying swaths of Gendarran Fields.
And considering I've got 4000 hours on my Guild Wars 2 account versus 40 hours playing Dark Souls, I think there's something particularly well-designed about the core of Guild Wars 2 despite its numerous flaws in many areas. But leveling isn't one of them, and neither is the fact that the game has levels. I play MMOs because I enjoy the persistent nature of their universe and the sense that I'm making it a better place.
And I think it's important that games like Guild Wars 2 "throttle" progression to make sure players are actually engaging in this type of content. That they're not racing to the end. Because Guild Wars 2 isn't about just defeating Zhaitan. MMOs are often just as much about the journey as they are about the destination, and I think levels are a great way of defining that progress.
But even beyond this fact, this game offers so many alternative avenues to progression. I got my necromancer and ranger to 80 simply participating in Living Story zerg content. I got my mesmer to 80 simply crafting. I got my elementalist to 80 in Edge of the Mists. There's so many methods of progression that you don't have to do a single renown heart. I have enough Tomes of Knowledge sitting in my bank from playing PvP to level three characters to 80 at a moment's notice. I have every class at 80 and every single time I did something differently.
That you relegate GW2's leveling campaign as a series of menial tasks feeding cows is quite simply pearls before swine.
Your description of it sounds interesting, and that is the sort of progression I would like to see in an MMO. However, either you are sort of playing around with the truth, or you are comparing too liberally with GW2, because the so-called "living world" do no such thing. What I would like to see is real change: a quest ("world event" or whatever), say, that begins in a city when an army captain marches his troops towards a bandit castle - and you and friends can join the captain and fight the bandits and if you do, the captain takes the castle and the next time you get there, it's full of friendly guards, the same ones that you helped to take the castle.
"But that is how GW2 works" - sure, but what I just described isn't living. It's dead as a doorknob: sooner or later the bandits retake the castle, or worse, the guards just leave it, and then the whole thing repeats itself. You get to follow the same captain, with the same guard company, to take the same castle from the same bandits. Forever.
Does DA:I work like that?
There are still centaurs in Queensdale, you didn't chase them out. If you don't believe me, go there and check. You did absolutely nothing to affect the world. The centaurs are still there, together with the rat-kobolds ("skritt"), bandits, and so on. Oh and it gets worse: not only did you do nothing, but if you just go to the place where you did nothing and wait a little, you'll see other people running around there doing the exact same nothing that you did, proving that your efforts was even more worthless than they appear on the surface.
GW2 is just about defeating Zhaitan bro; clearing out bandits is the city watch's job, they don't need you for that (as evidenced by the fact that you did it and the bandits are still there). But aside from that, your argument about throttling is the entirely wrong one: if the content was engaging to begin with, players wouldn't need to be forced to engage in it, they would do that on their own. And if it's not engaging, why would you want to force players to engage in it?
Think about it: if some content is not engaging, players would only go through the motions because they expect to unlock more fun things later on. But why then make that content not engaging? If you want players to play it, why not just make it fun?
(I refer you to the GW1 Prophecies campaign where you could skip all but four of the missions, yet most players did them all)
The real reason why throttling is done is to extend time played. It's part of the classic Skinner box setup, and GW2 doesn't even do it right.
And then of course you talk about avenues to progression. GW2 have a lot of those, because everything you do in the game (including logging in) is rewarded somehow. How do you motivate that your mesmer is a powerful spellcaster when all he did was do crafting, though? How is that playing a role? Not to mention, how is crafting anything but menial tasks?
No, it is not a question of pearls before swine, because there are no pearls here. I think that a more appropriate metaphor is about how swine will eat just about anything and still be happy.