To me, this is the film about overpopulation, and the responsibility to stop making so many kids. Kids are everywhere, in every shot, like vermin. the scenes they all sleep together. The mother pregnant again. The message is very clear, and I agree with it.
I do not agree that parents are caricatures. I would not say so. Acting is great. Whether these issues exist, I cannot judge but I think they do. The script is not perfect, true enough. It is not a masterpiece but it is courageous to bring attention to this issue no one addresses.