I do not want to party up to complete a personal story. I do not want to play as a thief.
It is rare enough that new content is created – and I really enjoy seeing the story unfold, but this is just frustrating and annoying. If I want to play as a thief I will switch to the character I created and took to level 80 and play a thief. I do not enjoy the play style of thieves, and I never will. Give me the option when I enter the mission to CHOOSE whether I want to play as the main character or as a companion with my own class.