Hmmm. An interesting set of responses.
I think that, perhaps, some of us have different beliefs on how much blame one should assign subordinates for participating in atrocities.
That's probably where a lot of the issues come from. As a subordinate, especially in the military, you have to assume your superiors have a good reason to do what they do. They have more intel, they have orders from even higher up, something. If you start to second-guess every order your superior makes, then you no longer have a functioning force. The templars are already held hostage to the Chantry by their addiction to lyrium, and I wouldn't be surprised if superior officers were the ones to give out that lyrium, to help build up a level of trust and dependence. They're probably indoctrinated.
I'm not trying to excuse Cullen's inaction, but, I grew up an Air Force brat, so I have some... sympathy for him? I want to know why he stood up when he did. Did he know about everything happening in Kirkwall? How accountable is he for what happened? I want to know how he felt about it then, how he feels about it now, and if he can make up for it.
That could change how I view his character.