Well, excuse my similar generalization, but the loudest PC gamers tend to be intense elitists. They think they're better than console gamers because they have their own customizable hardware, a "better" and more customizable control scheme, and... no real reason. Again, it's a generalization, and I'm aware that it's more a loud minority than an actual majority, but it is nevertheless the background of the phrase.
Compare it to PC people hating on Mac users. They claim Mac users are dumber because Macs are easier to use, when in fact, "easier to use" is hardly a negative thing. They just like feeling better.