Well they're big on their religion here in Thedas. There's some old stupid folk legend that a bunch of mages got too power hungry and tried to send themselves to God's kingdom, tainting it and ruining it for everyone else.
So there's this one nutjob religion who thinks magic should only be used to serve man and not to rule them and that everything horrible ever since is all magic's fault, and those people lock their mages up in places called 'circles' and make them eke out meaningless existences without ever even getting any (consensual) sex.
Then you've got this other religious faction who basically thinks magic is the source of all evil and mages can't even speak or they'll spread their evil horribleness.
It's just stupid, really. I mean fine, sod it, some mages are batshit crazy and get involved in kinky things and keep slaves and all of that shite, but go and stab THOSE bastards and leave the others alone, I say.