Because why would imprisoning people, keeping them under constant threat of the sword, depriving them of basic freedoms of movement, association and property inheritance, and filling their heads with Chantry superstition about how dangerous mages contribute to them becoming abominations?
Again with the JAnders koolaid. What you call: imprisonment, threat of the sword, Chantry superstition, and a lack of freedoms... other Circle mages have called: sanctuary, personal guards, religious education (of their own religion, for most of them), and amenities.
What I see here is this very short-sighted argument that freeing the mages will make them happy, and happy mages do not become abominations. That falsely assumes all mages would be happy with being out of the Circle, to begin with. We know there are a significant number who would not. Second, there are all sorts of potential stresses in the outside world that could do a mage in. The Circle rids mages' lives of much bigger stress than those it may create: impoverishment, hunger, illness, natural disasters, just off the top of my head.
That also brings us back to the original point: if a magical disaster is going to happen anywhere, better that the damage is contained rather than free to spread like a wildfire (possibly in a quite literal sense). Connor's example has been cited several times, and as noblity, his life was more comfortable than most!
If you've played the mage origin, you would know the first statements are false. You have no idea what it entails and Greagoir reproves Irving for giving you too much of a clue. As a bonus, it's barbaric.
I did play the mage origin, and am not surprised to see this nit-pick.
It may not be clear to them exactly what it will test, but they know it is something where they will have to call upon their previous training. And think about it: if the point is to test the mage's integrity against the temptations of a demon, isn't giving away too much pretty counter-productive to the task at hand? And what you seem to be implying, that the Templars want to stack the deck against the mage, is suspect: it is not in their interest to fight another abomination. Also, sometimes mages and Templars get along (*gasp*). If you've played the mage origin (
), you have seen an example of this in Cullen (sorry, it was more than merely getting along).
Nothing false about the rest.