@Dwarftank Couldn't they just isolate themselves in some corner of the Deep Roads nobody goes too? Seriously the Deep Roads AREN'T Dwarven Territory anymore and they won't be even if the Dwarves start winning it takes many generations to effectively recover any single thaig. Once you take out the Archdemons and the Darkspawn are cured of the Calling they literally have no reason to try to go towards the surface where they literally ALWAYS lose and die. That was part of the Architect's argument.
Also if the Calling can be cured...Why not the Taint itself? We might find out we could in fact render any negative of the Taint ineffective in the future. (Literally what the Dark Ritual and Fiona's fate majorly hint at.)
My main problem is causing the genocide of a Sentient Enslaved Species despite having the chance for Peace. If we're wrong to spare him we could always fix it later by killing him. If we're wrong to kill the Architect and he doesn't come back then we just negated the one single chance to end the Darkspawn Horde/Blights peacefully without the loss of more lives. I'd rather take the chance of sparing him myself and yes I consider it the ethical thing to do. He was right any evils he did so did the Wardens from the other side of the coin...If we're to condemn him we should also be condemning the Order otherwise we're the amoral hypocrites.