People keep pointing out that you can change these character's alignments in play as though that changes the fact that they're starting from somewhere. They aren't coming into this world as morally blank slates. They have beliefs and feelings and ideals that are currently informing their actions. That you can change them through your own actions doesn't change the fact that if left to their own devices, they'll be something. Shadowheart, if left to her own devices, will continue to worship an evil religion with zero hesitation or compunction. Gale will continue to be at best a hubristic fool who'll probably endanger whole cities because of his certainty that he has everything under control. Lae'zel will be typical githyanki and Astarion will be sadistic, cruel and hungry for power so he can topple his former master and probably take his place as an equally terrible monster. Wyll (pre rewrites at least) would probably go on being an easily manipulated tool of his patron. This is who they start out as, and however much you can change them, if you take issue with those starting points then you may not connect with them enough to WANT to see them change.
This^. So this.
Frankly I am baffled by so many people's inability to understand this point. It's not a complicated point. So I have to wonder, is it really that people don't understand this, or is it that they do understand it but don't want to acknowledge it for whatever reasons.