That's true, liberation won't solve magic's problems but it will lead to a new situation/outcome. Mages not locked into their circles, more mages out in the world. How would sticking them all back into their prisons move the narrative forward in any significant way? It kills progress. How will anything have changed? It's not the destination but the journey? I'm sure people will eat that up.
Since the Dragon Age franchise has from the start disavowed any central narrative equivalent to the Mass Effect trilogy, anyone who isn't eating up the premise of the journey rather than the destination will be eating crow regardless.
Otherwise, I feel you lack imagination if you can't think of how a failed rebellion can serve a larger story in various ways. Future mages and reformers having to struggle with not only the rebellion's defeat, but the sins accumulated in their name by those who ended up vindicating the fears of others. Considering how much of the pro-mage movement rests on the claims that the Circle system and its culture of supicion and doubt of them can't be justified by the crimes of the distant past, mages having to deal with the crimes of the immediate past and fellow travelers even as they continue to pursue the same goals can be an entirely different story to be told.
Sure, mad dogs can be put down. It's simply too bad that these mad dogs aren't going without a fight and have all the more reason to cut loose and use any means necessary to defend themselves. Not to mention fostering more resentment in mages, whom families will be even more inclined to hide. So stands the risk of Connor occurring again. I daresay that it would only serve to create the monsters that they seek to destroy.
Mad dogs fighting back doesn't change the nature of the mad dog... or why you would fight one in the first place.
Since any institution invites blowback and opposition, the argument of 'the risk of future Connors' is little more than an argument of people attempting to defy and circumvent the institution. It doesn't invalidate why the institution exists (sweet little boys like Connor can do horrible things for the best of reasons), nor does the abolition of the institution end the underlying nature of what caused the Connor (family, love, and desperation).
Unrealistic ambitions meaning what? Standing in the rain and kissing a girl as Emile De Launcet would say? Mage freedom is more than likely an inevitability.
The unrealistic ambition being the equal integration of mages into open society.
Mages freedom is more like an inevitability in the same sense any institution is only an indefinite, not permanent, arrangment. But then, mage domination following mage freedom is even more of an inevitability, even quicker, given the self-catalyzing nature of mage power allowing the accumulation of mage power.
Of course, being a member of the nation-state I can quite get behind the idea of a temporary but indefinite system that pushes the statistical inevitable (any non-zero probability eventually occurs) back as far as possible. That's quite frequently what we do in our own world and lives, after all, and at the end of the day I feel the hyper-majority of Thedas have a greater right to refuse to be mage-dominated (again) than the hyper-minority has to claim the ability for a chance at it.
Which isn't to say that anything against mages is justified- that's a strawman for the next person to claim so- but the mages can be expected to be marginalized from access to power, which also includes the steps and conditions to get access to power (like free movement). [They can also be expected to resist this, but that's irrelevant to the premise of a society's consensus.]