There is a thing we do where we project our own attitudes towards religion onto others. So if we're not dictated by religion, or don't think it could actually give mandate to cause harm, we believe other people are the same way and simply use it as an excuse. The west does this toward all religious conflicts and groups the world over. Religion doesn't have the same hold on us, so we don't think it has that kind of hold on anyone.
I think that's a pretty big mistake, a bias we should try to look past. For a lot of people religion IS true, it's not just a comfort or cultural practice, or something vaguely "spiritual". For a lot of people it does dictate behavior, it does give mandate to harm, it does demand and instill certain values.
The practice of constantly shifting any causation away from religion is grounded in our own bias. It's certainly appropriate in many cases, but it's not a rule that you can blindly apply to everything because the idea that religion could be bad makes you uncomfortable.