One of the criticisms I've seen DA players have in response to Anders' actions at the Kirkwall Chantry is some degree of, 'his actions forced innocent mages into a war they had no choice whether or not they wanted to be involved in'.
What a lot of these players seem to miss is this: The mages were already involved. They have been involved since childhood, when their magic manifested.
If you are born a mage in Southern Thedas, you are marked. The Templars will find you, or your neighbors who were conditioned by the Chantry to fear magic will turn you in, and you are brought to the Circle where you are at risk of Tranquility, or Annulment, and subjected to a Harrowing. Your children born to you in the Circle will be taken from you to be raised in a Chantry orphanage (like Wynne's child was). You are not allowed to get married, or start a family, or own land. You are not allowed to leave your Circle ever, unless conscripted to fight in the army (like in the Fifth Blight) or fulfilling some whim or need of those in power (like Malcolm Hawke being made to entertain nobles at a party). You might be thrown into the dungeon and left to starve to death, like the mage child Cole (and other mage apprentices of the White Spire) did. You are at risk of physical and sexual abuse, like the mages of the Gallows were.
Innocent mages were already involved. They were already being killed, they were already fighting for their lives for centuries since the inception of Circles, long before Anders' actions.
Also, in the case of the Gallows specifically, Knight-Commander Meredith had already called for the Annulment as early as the beginning/mid of Act 3. The mages' lives were already in danger, even before the Chantry was destroyed.
Anders tried for six years to make people listen and show how magic is not meant to be feared and can be used for good -- by publishing a manifesto, by providing free magical healthcare in Darktown -- to bring people's attention to the plight of mages and change things for the better. It took the imminent threat of his people being slaughtered wholesale for him to resort to what is aptly titled 'The Last Straw'.
If players want to blame anyone for subjecting mages to a conflict they did not want, look no further than the Chantry and their system of exploitation and oppression over the mages. Put blame on the Chantry for forcing mages into lives they did not choose, and asserting methods of culling and control over them, simply for how they were born. It was the Chantry that gave them no choice whether or not they had a say in staying alive or dying.
And if DA players would still say that the mages could have tried for a more "peaceful route" to alleviate their circumstances (despite seeing how Anders' manifesto, his Darktown clinic, and years of trying to negotiate with Elthina failed and Meredith was calling for Annulment anyway): very rarely do the oppressed win change by pandering to the morals of their oppressors.
Innocent mages were already suffering and being murdered in droves, for centuries. Innocent mages were already involved in this struggle, whether they wanted to be or not. And Anders' actions at the Chantry was like a rallying cry: If we're going to die anyway, then I'd rather die trying to take them down than giving them what they want.
(Also, I have not yet gone into detail on what actually started the mage-templar war, which was the Seekers hiding the cure for Tranquility, and Lord Seeker Lambert's decision to dissolve the Nevarran accord and take the Templars hunting for the free mages across the countryside because he decided dead mages were better than free mages -- because that's a whole separate post.)
