I wonder if a single FO4 player has actually gone "Oh no, I have to find my kid!"
I just sigh when I think back to Todd Howard sitting there, talking about how you'd get to know your character BEFORE the war, so you'd feel much closer to him/her and the family, and it would resonate more, and then you start playing the game and the whole pre-war stuff is literally over in five minutes.
They should just take a page from the modders' playbook and give you a "choose your own start" deal. Do you want to be a raider? A mayor? A BoS guy? And just go from there.