Ya, I don't get it either. When I was preggers, I didn't tell my mom until I absolutely had to (I was married, no issues) because I didn't want to hear the stories. Sure enough, first chance she had after finding out she started. So I told her that I'm not her and if she doesn't have anything supportive and positive to say that she should talk about something else.
I still hear this stuff all the time, either to me if I goof and tell somebody something, or a person's tale as it relates(?) to another person's current situation. I still tell these people to basically shut up. The level of rudeness depends on the story-teller.
I also don't understand the constant complainers. My wrist hurts - I hurt my back - I have bowel problems -- yada yada yada. OK, y'know if I'm your friend you can cry on my shoulder; I'll be tolerant and even empathetic in some situations. But if you are someone I work with or for, or meet every other week at the grocery store, keep it to yourself or find someone else to be your friend. Why, oh WHY do these people think that I care when I don't even know where they live? Really.