The son was a little beep and the daughter was likeable at first by by the end I was wishing she'd get killed just to stop her constant screaming from battering my ears.

Basically, I agree, but I think that only Robbie needed to be eliminated. Then, a less screamy Rachel would have made for a perfectly serviceable child-in-peril movie.
Spielberg missed and easy one.

The story is king.

Now that you mention it it is true that a lot of movies out of Hollywood feature atypically negative Amercian family situations. I am not surprised.

E.T. - absent father
Indiana Jones & The Last Crusade -
"it was just the two of us, Dad. It was a lonely way to grow up"
The Color Purple - dysfunctional family
A.I. Artificial Intelligence - dysfunctional family
Close Encounters of the Third Kind - dysfunctional family & absent father (cos of them pesky aliens)
Jurassic Park - absent father (and mother) + annoying kids
There's probably more.

Really? What other movies where that's a motif? Anyway, the dysfunctional family stuff seemed unimaginative, unnecessary, and annoying to me. If the story could've used a negative family situation to contrast with them pulling together in crisis there are more effective scenarios.

IMHO, the writing is seriously flawed by the unnecessary and annoying distraction of the dysfunctional family story.
True, but this is a Spielberg film - dysfunctional families/absent fathers are part of his motif. It's like he can't help himself.

IMHO, the writing is seriously flawed by the unnecessary and annoying distraction of the dysfunctional family story.