CNN, MSNBC, Fox news: Why bother?

One of my favorite posters, Alternate Universe, asks why liberals and centrists do not boycott the biased corporate media. She's got a point. Why do liberals bother appearing on the O'Reilley Factor when they know he's only going to misconstrue what they say anyway?

Corporate media, biased? Hell yeah. Everybody on both sides knows that. However, my liberal droogs, we must continue to participate. 1. Intelligent debate is impossible when both sides spend all their time bickering on whose source is more wrong. 2. When the liberals leave, the mainstream will grow even more biased.