Woman in the link is awful and I'm sorry for her kids.
BUT, there is such a thing as gender disappointment and I've met plenty of women who do clearly think girls are better than boys – for reasons such as they are more girly, you can do girly things with them ([hmm - I hate this - because what if you have a girl but she's not a girly girl? way to make your child feel like a let-down), they aren't noisy and boisterous (again
perhaps if you constantly disapprove of your girl for being anything other than decorous, she learns) and at the other end of the scale, extreme feminists who hate boys for being male. We grew up with one of these on our street, she was a single mother with a boy and a girl, she openly and to extremes favoured the girl, and would slag the boy off to other people in front of him. :(
I think in the main though, if you have a boy, you will realise that having a boy is fab. The main offenders IME, among people I know, are the SMoG type - they have only had girls and think they are sooooo lucky and look pityingly at you with your boy/s, and may say things like "Oh i do feel so lucky that I just had girls" and "boys are such hard work, poor you." They tend to be middle-class types whose girls are dressed head-to-toe in matching frilly Boden and go to private school.
I am not exaggerating, I know a good handful mums like this just in my circle of acquaintances/other mums at school & nursery/neighbours.
Just because in the world at large, there is much more prejudice against girls which I agree is awful, doesn't mean it's OK the other way round. That pitying concern that I have to put up with a boy gives me the rage.