Ah, the glorious PC-gaming master race, that mental image always cracks me up. But in all seriousness, consoles are essentially PCs after you strip out almost everything a PC can do besides "play games".
While some PC-gamers are probably being superior just to be a jackass about it, a fair number of us are smug because watching slavering advocates of the collectively inferior (to the PC) consoles argue amongst themselves which is "teh bestzors!" is inherently hilarious (and also terrifying when you realize that most of those fanboys will one day be old enough to vote) in the same way that laughing at the antics of stupid people generally makes one feel better about oneself (for not being stupid enough to do whatever it is that the stupid person was doing to make you laugh in the first place).
As a PC gamer, the notion of getting into heated internet debates over gaming console is as absurd to me as the notion of heated debates over television sets or DVD players would be. They are bloody gaming appliances, not 'political affiliations' or 'lifestyle choices' for crying out loud!
But just try telling that to a fanboy.