Gwen (as kid): Healing and boons
Melandrus Stalker: Fierce tank
Prince Rurik (undead): All sorts of corruption and conditions
Livia: Decoy (against male players). Envy (against female players)
Non-Playable Canthanian: Knocklocking shouts and the like due to bad voice acting.
@ the usual flamers. My cousin stopped playing soccer because the playstyle went from 'play how you and your team sees fit' to 'rehearse this specific technique days on end'. Assuming that he stopped because he didn't care about winning or because he wanted to play solo just shows how some people create arguments out of thin air to support their case.
The analogue to GW2 is of course that the game changes when you change the way you play it. I totally understand that some players want to get the most loot or gold out of their time, but I guess that for this game and for soccer and for practically anything else you can do, if you min/max everything maybe there isn't any space left to actually enjoy what you are doing.
Arkham, I am so much on the same page as you. GW2 is a game and every single game in the universe can be fun or un-fun to play, depending on how you play it.
I have a cousin who played professional soccer and he got to a level where he was demanded to play in a certain optimized way if he would continue his soccer career. He stopped. The game had been fun to him until focus shifted to optimization, then it was boring.
I do not think it is possible to make an MMO without players trivializing it. I think what game developers should do is to create the game they want to create. If people plays the game in a way that isn't fun to them, those players should simply stop playing. The rest of us can have fun until we don't.
@Kymeric: I think they have a testplayers that try out how for instance the mighttweaks work before releasing them. I am aware that the results may not translate 1:1 into the entire playerbase. I get where you are coming from, that you should introduce one change at a time, but on the other hand, if they could never do some semibig changes the game would evolve pretty slow (and people would probably be screaming for moar changes).