I didn't. I think the writers really screwed up on the final act. There was really no point for a mage to side with the Templars to become Viscount. It did not make sense to me from that standpoint. For a non mage Hawke its understandable but not for a mage Hawke.
And the fact there was very little development with Orsino still angers me. His introduction was the most jarring experience of the game for me.
At least we got an idea of who Meredith was in the beginning of Act 1. Orsino should have had a better introduction.
The supposition, then, is that a mage only ever supports the notion the Circle is inherently wrong or bad. And if you play Origins, you know very well mages themselves are all over the map in varied opinions on that particular question, rather. The largest number of Circle mages, in fact, consider themselves Aequitarians, moderates who advocate a reasonable respect for the rules and regulations of magic in Chantry law.
There's a point during Legacy where Malcolm Hawke can be heard admitting his fear that his unborn children might be mage-born. It seemed to me, then, that Malcolm wouldn't be likely to teach his mage children that magic was some awesome gift, or anything they should be glad for. But rather a burden and a challenge they needed to respect.
My own mage Hawke, then, wasn't keen on any notion of Mage freedom. He saw his own situation as one of obligation and responsibility, rather. There were many instances he would've been glad to give himself up to the Circle, except that he was constantly needed -- by his siblings, his mother, his dang dog, his friends, the city of Kirkwall ... He was really tired by the time all was said and done.
And don't forget how many blood mages Hawke encounters. At every turn, he's fighting someone who's turned to blood magic. There's Tarohne, Decimus, Idunna, Grace, Alain, Quentin. He sees people forced to become abominations, demons forced into them, the dead made into shambling skeletons, his own mother ripped apart and stitched back together. And then it's a mage who obliterates the chantry, killing numerous people to score some political goal that he himself doesn't necessarily agree with.
No, my mage Hawke had very good reasons to side with the Templars. From his viewpoint, magic required restraints, and the Templars were those capable of providing controls that magic obviously needed. He respected them, and all that before his own brother wore the shield, too. My Hawke would never choose to fight against his own brother, shrug. He'd already lost too much by then.
I'm looking forward to seeing Hawke in Inquisition, mind you. That was my most favorite playthrough of DA2, and he remains my canon Hawke.