All the boy vs girl guff aside, I'm afraid I have to agree that girls seem to be preferred over boys with many people. I don't think people mind having boys as long as they have at least one girl.
A number of posters have expressed that they have had people say 'what a shame' when they have another boy, yet you don't get people doing this when someone is having another girl. Indeed, people seem to congratulate them.
I've actually had a number of women I know (several so-called friends, and even a cousin) be really offhand with me, because I produced a girl and they didn't. One cousin of mine Linda - 7 years older than me - had 4 boys over 12 years, and actually cried when her 4th child was a boy.
She had an alie though - another cousin of ours (Laura,) who was also 7 years older than me. She had 3 boys. Laura seemed a lot more OK with it though, and loved her 3 boys.
Then my firstborn was a girl, (This was early 2000's,) and Linda went utterly batshit. Completely off the rails. She was 36, and threw herself down on the floor in a fit of rage, screaming and hollaring 'why does SHE get to have a girl? Why didn't I ever have a girl?' And she wished some nasty shit on my daughter that I won't repeat on here. I can only put it down to some weird personality disorder - or PTSD after having a 4th boy that she didn't want - but I will never forgive her, and never spoke to her after that. (Over 15 years ago.)
Linda clung to Laura like a limpet, and continued to slate me, but to her sheer horror, when my girl was 3, Laura had a 4th child; a girl. Linda was incandescent with rage and anger, and ended up alienating Laura too! She flat out blamed her husband for it all, saying he wasn't 'man' enough to produce a daughter.
Several years ago, she and her husband split up, and all four boys have left home now; 2 went to uni and stayed in their uni town, and the other 2 just left and moved in with their girlfriend. Not surprising really after having a batshit mother who blamed them for being male!
I know this is an extreme case, but it's just to illustrate how some women are a lot more upset and badly affected if they don't get the daughter they want, than the women who don't have a son. No idea why, as boys are just as valid as human beings as girls. It's just some women need to have a daughter, even if they have 3 sons, they don't care, as long as they have at least ONE daughter.
In addition to my cousin Linda, I have had friends in the past, (who have boys only,) who distanced themselves from me, once I had my girl. They were resentful and bitter, and made some really rude comments about little girls. Yet I never once - EVER - said anything negative about their boys. Some friends with boys were fine and never said anything bad, but yeah, a few of them couldn't handle me having a girl.
I had a boy too by the way, 5 years after my girl, and I love him just as much, they get on brilliantly, and he is amazing (like she is!) However, I have to say, I did want one of each. I would not have been devastated with 2 boys, but am very happy I have one of each.
I do have to agree with a pp sadly, that brothers are less likely to get on well than sisters. (or a sister and a brother.) I know many families where brothers either have very little to do with one another, or they have not spoken for decades. It doesn't seem to happen so much with sisters. (Or a sister and brother.)
I also have to agree that adult daughters are much more socially active with their mothers than adult sons. As a pp said above me, many young men are quite embarrassed to be seen with their mother shopping and 'doing lunch.' Maybe when they are older - like 40-odd, but daughters are far more likely to want to socialise with mum! (and dad!)
Finally, I also agree that many men want daughters too. (And they don't all secretly want sons only...) I think many want sons, but they want at least one daughter.... The excitement was paramount in a few men I know when they and their wife produced their first daughter. I guess there's something about a daddy/daughter relationship that is quite precious. My cousin Laura's husband was delirious with glee with their little girl, after having 3 boys. And even over a decade later, they are inseparable. He ADORES her. 
And like me, my husband thinks the world of both of our kids, and like me he is glad to have one of each. We love our boy, but must admit, we would not have wanted 2 boys.
- linda and laura are not my 2 cousins real names.....