I don't think this can be construed as 'fanboy dismissal', though the term 'fanboy' itself is controversial.

Post purchase dissonance reduction is a well known cognitive bias[1]. And what can be better for dissonance reduction than someone telling you that you have good taste, and anyone who buys the competition is a philistine?

I should point out that this does not impute anything to the quality of the products themselves. I just posit that blogs such as Gruber's play a active part in the ecosystem due to our cognitive biases. They are not merely a passive observer.

[1] http://en.wikipedia.org/wiki/Post-purchase_rationalization