So because potentially Hawke can agree with that lunancy it should be acceptable even to Hawke that's don't? I don't follow that Logic.
And comparing video games to reality is the basis for much of the arguments in DA.
Improved rights, the removal of the serf system and slavery, Those concepts are within both our own Medieval lore and DA it self and yet we apply the judgement of the modern day to them when in those times it would be nothing to scoff at. Point being you cannot walk a two way street on the issue allowing modern day concepts into a video game with it also not being interpreted as negatives of the same historical precedents.
So you try to apply the norms of a post merchantile democratic society in a pre-merchantile feudal society. Truly nowadays such an act of terrorism is abhorrent, inexcusable and not an effective carrier of change. People react to exercises of strength or violence in a different manner and a non agressive approach is much more plausible because most of our societies have democratic regimes or even before those at least in the past 3 centuries there was a diffusion of authority because of merchantile strength and the rise of the burgeois against the feudal system. Dragon Age is clearly a feudal society and not a particularly enlightened one politically. The common people have no electoral power and very minor purchasing power. The feudal lords have very limited electoral power which is under the constant censure of military and religious power centers. Ferelden is perhaps further advanced because its existence is in opposition to Orlais; their nationalism is defined in opposition to Orlesian norms and it is well likely that the Orlesians could reclaim it at any moment. Kirkwall is much different. Its viscounts are presented to have ruled under the approval of the chantry and templars. If the common people rebelled against Meredith, she would simply put them down; in fact Leliana makes it pretty clear that the Divine might well put the entire city to the torch.
In this balance, one should consider the choice made by Anders. Perhaps change could be accomplished with a moderate approach but it would not take decades, but rather centuries. Not until the economic and political structures could support rights movements would the Mages be able to tap to the concordance of the collective to force political reforms. In this time we are weighing a likely short though violent war against the current situation. Templars do not simply incarcerate mages. There are extensive instances of molestation and rape, constant psychological violence, and the right of tranquility which is not only murder of free will and some sort of slavery but also largely economical exploitation; the skills of the Tranquil in enchantment partly or perhaps fully fund the Chantry and the Templars. All I am saying is, do not compare what Anders did with examples of social reforms in the past century cause there is no analogy. Rather consider any instances of actual social reform taking place peacefully in the Dark Ages.
I said this a dozen of times already, you cannot apply modern ethics to DA and your comparisons were quite modern. For example the genocide of other nations was a mark of honor in Roman Empire. You should look at what Anders did with this mindset not your current one.