I think everyone has an internal battle between what they know they should do, and what they want to do.
That doesn't mean we all want to be axe-wielding psychopathic rapists but know we should really be "nice people" ... everyone's struggles and the extremes of what they want to do is different.
But I think if you look at things this way it's less of a surprise when someone seems to switch from being a campaigner for or against a thing, to being a proponent or perpetrator of a thing.
Similar to how the ultra-Christian TV evangelists gives in to their "inner gay" after years of speaking against it so vehemently, or why the biggest advocate for children can turn out to be a secret pedo.
People know what they should do, they may put effort into doing it, and it may be to mask and suppress what they want to do.
It's sad if they don't recognize this and get the help they need, and instead try to cover it up.