How is that a flaw? They have SIX HUNDRED MILLION USERS.
People want junk food. That's why everyone is fat and dumb. They watch junk on TV, read junk online, say junk to people on facebook, and eat junk at home.
0.000001% of people care about privacy and control and less apps & games.
Allow me to categorize my friends into work, friends, family, public categories and you're on the right track. Come up with a novel way to communicate with each other.