That's a good explanation of what your startup is, and I wish you the best of luck, but you did not answer his question.
As more of these groups are formed we aren't exposing what groups you are in to other people joining. In fact other people joining don't know who else is on the platform unless they are in a group with them.
So this social graph that is being built isn't based on friend requests that have little inherent value but on the different groups you are part of that are based on specific relationships.