[@McHaggis] Okay, remove Bethany from this equation because in truth, it is a grey choice.
But as stated, Mages can use anyone for fuel in terms of magic, and this is proven.

Yes, Ferelden's circle was pretty nice and not all Mages are bad.

Petrice was a bitch, and not a Templar, in fact she is why the Arishtok attacked to begin with. 
Also, Isebella is another reason why the Qunari were even there in the first place. 

So yeah, Collectivly the Templars can be dickish, and even do vile things because they are people like anyone else.
But even then they mean well as an order by keeping others away from those who could otherwise sacrifice for power. Yeah, don't even pretend mages don't do that.

Also, let's not forget the large hordes of mages that flat out defect that just straight up do blood magic so they can basically say "Fuck everything." And this was long before the Templars increased their grip. 

And, if you have a high enough realationship with Isabella, she stays with you anyways. So it isn't about what is "appealing" to her and your sister. 

Let's also not forget Meridith is just a cruel character that even her own men side against. They are not for killing innocent people, but the tower became so corrupt because of revolts. 

I rather same the many nameless factions vs the one faction that can use anyone as fodder fuel.