Eloquent, but you're still defending a generalization. The "mainstream media" is the elephant and you're only describing one leg. You put up the Times as your example, and you'd be right if you said that the New York Times has a liberal bias. But you've chosen one of the most obvious and extreme examples and called it representative of the whole. A is B, and A is C, so B must also be C. I could just as easily, and just as incorrectly, say that Fox News proves that the media has a conservative bias.

The notion that the media has a singluar, guiding ideology, other than profit, is championed by ideologues who need a cause to keep people tuning in (so they can profit). Diversify your news sources, and the bias goes away.