Look, in all fairness to both sides, they were turned into crap by the game.
Mages - lore wise they are the ones to be pitied - they turn to blood magic and demons because they feel backed into a corner with the Templars going around abusing them (and with hundreds of new tranquil (at least according to Orsino and Anders) filling the Gallows, it's evident that quite a number of Mages are being treated less than humanely by the Templars. Game play wise, however, in order to make the fights harder and the story more murky, they make nearly every random mage encounter have abominations and demons and blood magic at their disposal.
Meanwhile, the story makes out to turn the Templars into demons. Mages are threatened with sexual abuse, the "tranquil solution", and in general being sadists. There are three named Templars who are not complete sadists or sycophants - Keran, Thrask, and Cullen. Every other named Templar is a mage hating sadist (or Qunari hating sadist in the case of Varnell), and the random templars in the background are either just fine following orders they know are wrong, or are too timid to say anything against it.
That, ladies and gentlemen, is an attempt to make the choice for us "difficult" and "moral". In my personal opinion, it was the choice between two bowls of poo, the only difference between them being that one was more self-righteous and the other more abominable.