Why are people so weird about people posting pregnancy updates on social media?? A friend of mine…

Why are people so weird about people posting pregnancy updates on social media?? A friend of mine recently shared her gender reveal photos, and half the comments, from family and close friends, were basically telling her that no one cared about or wanted to see anything about her baby until they were born! Why the hostility towards someone sharing their milestones? And I know these people, most of them make sure to keep us updated about every molecule of food that enters their bodies, but pregnancy is crossing the line?