If it's good enough for the root zone of DNS, it's good enough for my friends list.
Yes. There is a real world outside of your room. People socialize.
Yes, there is a real world out there. As opposed to Facebook, which you mostly access from your room.
Yes, people socialize. Have meals together, go dance, study together, play and sing, and much more. But it happens in "the real world outside of your room".
Sure, you can use Facebook to facilitate much of that, but you can do that with a phone or a car or e-mail too. Yet that doesn't make people think that the phone or car or mail server is the venue.
You mostly access Facebook from your room? ("In Korea, only old people use email...") I access Facebook from my car, from the office, from the park, from a bar, waiting in line at the DMV, via text, etc...
It's a forum for electronic communication. Sure it's possible to primarily use it purely for random connections, but well over 90% of my Facebook friends I know (or have at least met) in person.
If you're asking "Why Facebook them when I could just text them*?", you're doing social media wrong.
*(outside of a disaster situation)