Sheesh, I'm not being hostile. I'm trying to explain my point of view, but the response I've pretty much gathered is "Well, yeah, you can do that but you're wrong".
It may very well be because I love making characters, and I love re-playing as classes I like. Doesn't really matter which game. Sure it's a bit different for an MMO, but for example I've played Mass Effect through a good couple times as the same kind of Adept Shepard I've always enjoyed it, and well... I still enjoy it. Back during WoW there was no way I would've wanted to roll two Priests for the sake of having two Priests, because the mechanics didn't change that much in my opinion. It just feels so different on Guild Wars 2; each class offers a lot of different things and playstyles you might enjoy, and wanting to enjoy those fully on more than one character just seems a bit more enjoyable to me. Like... I still feel pretty lost on my Guardian because of so many changes/variations you have, depending on what you want to do. I carry a god damn arsenal in my backpacks on her, with two full sets of armor and at least 5-6 weapons. I have and still am considering making a second Guardian who will use a different approach with combat and whatnot, because it makes it easier for me to keep things in order and I'll still enjoy both characters just as much.
And since gear/money/etc. isn't really an issue in Guild Wars 2 as pretty much all of it is shared account-wide, it just makes it really approachable to me personally to think about what kind of other variations I could enjoy having at maximum level. It might not make sense to some people, but to me and many others this kind of thinking makes a lot of sense. Some might see it as wasted time, but a time you enjoyed wasting isn't really wasted time and all that, eh? So, yes. I know I can do all these things on one character, but I might not want to. Some classes I'm perfectly happy to own only once, but I can easily find uses and justify (at least to myself) some multiples of some classes. *shrug*