If anyone was the true hero of that game, it was him, not friggin Anders who I gladly murdered after the dude casually assassinated innocents and completely ruined any chance for peace. In a way Anders was the perfect embodiment of the selfish mage who cares naught for the common folk who are (rightfully) a tad bit concerned about mages being living portals to rape daemons and prone to unleashing hell any time they get pissy.
The problem is that the whole mages being living portals for demons is a Chantry created problem. Remember that Tevinter was ruled by mages for a very long time, and while they were generally cruel and sometimes psychotic, being demon possessed living nuclear apocalypses isn't something that was connected to them. That is not to say it didn't happen, but it wasn't even remotely common and one of the things about Tevinter was that mages were recognised and trained early, which evidence seem to suggest help avert such things.
It was the Chantry that played up the demon possession aspect in order to bring the mages under their control as they believed that mages were a threat to their power (rightly so, if the Circle-Templar war is anything to go by). And because of that persecution, those mages that did escape the mandatory life sentence usually turned to dark arts in order to gain power quickly merely to survive the inevitable waves of assassins and templars ramming up their asses. Remember also that blood magic isn't as bad as the Chantry made it out to be. You can become a blood mage in the game, after all, and if you didn't want to play the mass murdering psycho, you can. Blood magic, like any other magic, is just a tool that mages can use.
There are many examples of mages doing good, but because of the demonisation by the Chantry, mages are persecuted and attacked and reviled. That creates a self-fulfilling prophecy when a mage finally snaps under the pressure and start hitting back.
"Oh mommy, that bad mage attacked me! I didn't do anything bad. Just called him names, try to get my friends to lynch him, threw rocks at him and his house, broke windows and doors a few times, made fun of him and all the usual things that we normal people do to mages since he turned up 10 years ago."
"Hey, everyone! That mage attacked my son! He must bake bread with the blood of all our dead children! Lynch him!"
"But we haven't had a dead child for years, except for Leeroy, but he was an idiot who got himself killed playing in traffic."
"They all got better! Now, lynch him, unless you are some sort of anti-Chantry mage sympathiser!"