Me and my group are starting to resent most of the penances, that either require one or more people to weaken themselves or otherwise hurt the team for their own personal gain, at everyone elses expense.
I would recommend keeping these in, but just moving the rewards to more team-oriented achievements. Like completing all Heresy difficulty missions gets you the 2nd to last armor, and doing all on Damnation gets you the final armor. This way people are motivated primarily by completing the mission, rather than sitting by themselves in a corner and asking their team to just kill themselves already.
I’m loving the game so far. 80 hours played and I don’t intend to stop anytime soon.