"And then I read the news story that modders have put child murdering back into Skyrim."
This should be called "allowing for Skyrim children to die," because that's the overall purpose. Alright, murdering them might be the main specific, but once a town's had a dragon fuck the ever-loving shit out of it, it is a little bizarre to see Little Timmy survive.
MW3's is pointless and lazy, simply allowing it in Skyrim is not really the same thing. If people are going to take issue with the latter, then don't play the games at all, because you won't be able to handle the fact that people will slit a hobo's throat for a carrot.
"The designers of Skyrim are trying to create a setting in which you forge an epic fantasy story. And whether your story is one of a fine upstanding swordsman, or a neutral mercenary, or a morally flexible assassin-thief, pausing on your way to work to methodically slice your way through a row of innocent schoolchildren is going to turn that story into something it doesn't want to be."
And yet you can spend 10s of hours picking flowers and making potions that let you sprint for longer. Hardly an epic, yet still an option.
The designers of Skyrim set out to create a world in which you can do whatever the hell you want; they don't let kids die because its deemed to be in poor taste because... well, because.