Youthful fascination with collectivism is in part simply a way to address perceived "unfairness." If everyone shares, then a young person arriving on the scene fresh will not have less than an older person who has been around for a while.
This is all harmless enough, but the pattern can be manipulated in dangerous ways. I don't want our young people aggregated, even by a benevolent social-networking site. I want them to develop as fierce individuals, and to earn their living doing exactly that. When they work together, I hope they'll do so in competitive, genuinely distinct teams so that they can get honest feedback and create big-time innovations that earn royalties, instead of spending all their time on crowd-pleasing gambits to seek kudos. This is not just so that they and their children will thrive, but so that they won't become a mob, which, as history has shown us again and again, is a vulnerability of human nature.