Isn't social networking a valid reason to join? The whole point of ET is to meet fellow artists and lovers of fantasy and sci-fi. Of course, I admit, there are many people on Elftown who are there solely looking for friends and aren't really that interested in art or writing... but not everyone is like that.
Anyway, I was just saying... Yes, people come to WritersCo to show their writings, to get feedback, etc. But what's wrong with making some friends while you're at it? It would make the experience that much nicer.