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.