Rather, it is a social activity where people share personal ideas on things.

It's been mentioned (on my IJ) that fanfic is not only social--that many people do this as a solitary activity for years before finding anyone else who does it, and that many fanficcers have no interest in the "social" aspects--they want to exchange stories, perhaps, but not to read commentary or discuss them.

The claim that "fanfic is a social activity" needs more careful explanation, because from some perspectives, it's not true.