I am visiting Italy for 2 weeks in July. I am sure that professional photographers have already taken plenty of pictures of the places I will see. Why shouldn't I just skip taking pictures and buy a book of photographs of places in Italy and then show it to my family when I return home? As I am flipping through the book, I would say... I saw this... didn't see this... here's the leaning tower of Pisa, I cimbed it... and so on... why should I worry about taking my own pictures? I can't rationally justify it.
(I own a point and shoot digital camera my mother gave me as a gift in 2006; it only takes grainy pictures in the evening or in low lighting; she feels like if she travels somewhere but couldn't take pictures, it would be the same as if the trip didn't happen, because she would have no evidence of her trip...)