The games are more for the middle aged player.
They have no list of long lost people they wish to connect with. Everyone is a friend or friend of a friend.
You can follow brands but the youth want to follow a band or an actor not a toothbrush company.
Things like poking or using a fake name or having permissions connected to school or orgs created social group that you would share related photos. Now you have to manage a list or share with everyone.
Facebook was a good way for college kids to connect with everyone from there school. They could create a new persona with fun photos/videos and show everyone how popular they are. Now you hide your friend list, avoid saying anything that you wouldn't say in front of your mother and secretly worry that anything you post will be purchased by a potential future employer enabling them to filter out your resume in record time.