Even those who claim to be in the moral right have been known to use ignorance against those they perceive as being different or unnatural to the world.

Any one of those could cause and in some cases even promote ignorance. Along with possible laziness... they don't wish to expend the effort to find out the truth of a given matter and thus accept whatever they're told of it as the reality of the situation.

Sometimes one might even continue down the path of selective ignorance, even after having been shown the truth, because they are too ashamed or too scared of what might happen if they admitted their ignorance and acted on the truth they have learned.