If the mother were punished for her callous treatment of her children, especially the youngest, then maybe her behavior would act as an anti-example. But as it is, with no repentance or personal consequences (only her eldest son suffers for it), I don't want this read to my kids. I don't want her behavior modeled for them. I don't want them to worry I'll ignore them if they fall down a well, or treat them differently based on their age alone. And I don't want them to feel that either of them is worthless. Not even in a relative sense.
Message
Chinese people are exactly like Japanese people, except with stupid (nonexistent) traditions. Also, among siblings, only the oldest son is important and everybody else is basically disposable.