So this is none of my business but i was just on fb and came across a story where a couple had 7 boys before they managed to have a girl. Obviously i dont know the backstory and this couple may have intended to have a large family regardless of the sex of the first 7 children. But i know several couples who have had 3-4 of the same sex and carried on until they got what they wanted (usually girls).
In my opinion if they'd had what they wanted in the first place they wouldn't have kept going which feels wrong to me, when i got older i wouldn't want to know i was only born because my parents were trying to have the sex they wanted.
YANBU- You agree people shouldn't keep having children until they get what they want.
YABU- People should have as many children as they like until they get what they want.