Why does everyone use PF as a representation of the game?

[Midareyukki]

again what is your source?
the vast, vast majority of the 28 million registered players never interact with pf, and of the small minority of those who raid, they will raid with their own group of 7 other friends and never, ever interact with the rest of the game population.

And where are YOUR sources? Because I can easily just come in and tell you that people tend to go on PF a lot more than sticking around in a static. Also, I wouldn't go for the registered playerbase, I'd go for the active playerbase. It's far fairer of a comparison.