Anders is by no means "normal".
He is just not as unstable as people think he is, I mean the friend type Anders. He destroyed the chantry because he wanted to, he can even be called evil for it. But he didn't do it because he had a breakdown or Justice forced him to do it. He has changed, its true, but it was not something unpredictable. He hated a system and decided to take actions.
Justice or Anders has nothing to do with it. It's Vengeance.
Anders is not evil. He's possessed.
My rant above though is that possession itself, as an concept, is becoming a "benign" thing in this setting too. Even that has to have a "good" side now.
I'm getting tired of their compulsion to show a "good side" to the most disquieting sh*t. Spirits and Qunari especially. F*ck both of these things.
If you want to know why people side with Templars, it's because of this. We like a little normalcy and sanity. A little craziness is fun, but not going all out with it.