It bums me out when artists who I really enjoy die, especially when they're still producing like Bowie and Prince were. Hell, I just saw Prince when he came to the Palace last year and he was phenomenal. I don't see anything wrong with sharing videos and celebrating that artist on social media.
That being said, I think people who seem to compete over how sad they are and have some angle about how they're destroyed by this random famous person dying, are just trying to make it about themselves, they probably do that with everything, and they're generally awful.
"You don't understand, I was bullied in high school, and every day after school I would go to my room and listen to p**** control and decide to wait one more day before killing myself, and eventually things got better..."