Why don't people mind their own business?

Recently my daughter was in the hospital to have a tonsillectomy. She had to stay in for 3 days and I stayed with her.
So, we got to our hospital room and met our new roommates. I've never met these people in my whole life and the first question they ask is "So, what are you in here for?" I said "For surgery." and I didn't elaborate further.
And I am not exaggerating but, every single visitor that they had in the next 3 days ALWAYS asked the same thing right when they walked in the room.
The worst was their grandmother. After she pried out why we were in the hospital, she went on to explain why her grandson was there in full details. And of course he was SO much sicker than my daughter, she made sure I understood that.
I just said "That's nice." and kept reading my book. What is the appeal with finding out details of a perfect stranger's life? I could have cared less why her grandson was there. I only cared about my daughter.
Do you ignore people like that or do you say something?

Edited to add: This wasn't in America. It was Europe. But, I am American and this wasn't friendly small talk. This was prying.

I am pretty sure they were just trying to be friendly. However, to answer your question. "Why don't people mind their own business?" It's like this..."Some people don't have their own mind and others just don't have their own business!!!."

It is called being freindly To not talk is just rude espcially if you are with in a persons private surronds.
and remember people = curiosity how boring woyld the world be if no one talked based on the fact it has nothing to do with them. It is also a way of letting some one know that they care even if they don't know you.

Because they are nervous and worried about their loved ones so they find comfort in talking to others, it makes them feel better, if you don't like making people feel better then close the curtains. I must admit that I am like you, and I think of funny ways to turn people off talking to me, but I'm never outright rude I just say something that I will find amusing, or when they walk in I'll start scratching my testicles

You could simply have said, "I'm sorry, but I don't wish to discuss it" -- and repeated that as needed.

The grandmother didn't pry anything out of you -- she wore you down.

Shared hospital rooms usually have a rolling curtain for privacy. Next time, avail yourself of it.

people that get into others buz don't have any thing going on in there life so they need to fill