Look, this is still the Forgotten Realms. Atrocities are commonplace. Entire villages, and even cities are wiped off the map regularly. Killing someone outright is actually not even close to the worst thing that can happen to someone in this world. Tieflings have never been commonplace in the realms, and never been beloved of the people. Everyone knows why this is, you can't help but look at the exagerated features that Larian created for them without being certain why people might think the worst of them. Are they all evil? No, they aren't all evil, but they are all tainted, and for some, even some Paladins, that would be reason enough to eradicate them.
This is a game. Everyone knows this is a game, but some people are here screaming about killing kids not because they care about these poor little digital characters, but because they want to control how other people live their lives and play their games. You want to scream about killing kids, then scream about the people killing and exploiting real live children. Get out there on social media, and in the streets petitioning your law makers and government oficials to do more to stop it. Once you've done all that, I'll give you credit that you actually care about children instead of just trying to force other people to do what you want.