You never know who’s going to turn out to be important further down the road – some biographer may be terribly grateful to have the juvenilia of a famous writer! Also, if novels, the penny post, bicycles, the telegraph, etc. didn’t destroy civilization as predicted, the world can survive Instagram, you snob!

Also, people have always documented their lives insofar as it was possible: it's why we have graffiti. Do I think there are issues with the branding and commercialization of social media? Absolutely. But I blame that more on capitalism than on the human desire to have photographs of oneself doing neat things with one's friends.