The original fallouts didn't have as much commercial success as something like fallout 3 and up, so of course they weren't too concerned about their audiences. However, the new fallouts are targeting a large demographic and need to omit child death in order to avoid people getting all over their ass.
Also just because the children are mere lines of code doesn't mean they don't resemble real children. The point is that simulated child anything is almost as bad as real child anything since you're essentially killing something that resembles a real child. When you play a game like fallout, the children don't look like walking lines of code; They look like real children.
Another thing: You say child murder is perfectly fine in a video game since they aren't real. So are you also saying that child love could be perfectly fine in a video game since they aren't real either? You really have no moral compass in video games so it sounds like you wouldn't mind doing such a thing. How about child torture? I mean, they're just lines of code, right?
