Authenticity doesn't mean you act in a way that the majority approves of, in fact it's often the opposite case. It also doesn't make any presuppositions about the morality of specific behaviour. To be authentic is to be your true self,
despite what others think which requires bravery and that is something people admire. If something is considered shameful is a subjective judgement about behaviours that may or may not be authentic.
In fact, people who act authentically are often liked not despite of but because of their flaws. To be human is to be flawed, we're all guilty. And it turns out a lot of people crave permission to not be perfect.