> Is your social dynamic interest-driven or is it friendship-driven? Are you going there because there's this place where other folks are really into anime, or is this the place you're going because it's where your pals from school are hanging out?
I believe those different groups are called "social circles", and Facebook started supporting the concept in 2011, after Google+ made it central to their interface. Facebook is the MEDIUM for different grugroups to communicate. Facebook is not the group.
Yes, it would be weird if every group gathered at the same physical location. It would not be weird if they all drove in cars to get there. Facebook isn't a physical space that crams everyone together. It's a method of getting to different groups a person belongs to.