How is it counterproductive? By what mechanism does complaining about the mainstream media actually make it worse? Complaining about the mainstream media may indeed fail to improve it, but saying nothing will certainly have no effect.
Complaining about mainstream media on mainstream media would be fine. Complaining about mainstream media on alternate media pollutes the alternate media with the problems of the mainstream.
Part of our frustration probably stems from the reality that the large media businesses will get by just fine without the readership of the elite clientèle of YC. [eye roll]
However, most of us probably do tend to influence the opinion of a few others. A little complaining (in a constructive way) might be useful, albeit in an indirect way.
I like to think of preaching to the choir (or disagreeing with them) as being a way of polishing one's persuasion prior to the full congregation (or converting the masses).
