I think they mean unbiased by the giant advertising agencies through which all major media's takes are filtered through. If you're watching CNN, MSNBC, Fox, etc

I think they mean unbiased by the giant advertising agencies through which all major media's takes are filtered through. If you're watching CNN, MSNBC, Fox, etc, you're watching what their advertisers approve of. And usually that approval is "The hottest take that, causes the most angry tweets, that gets the most views, of our dish soap." But also sometimes corporate politics bleeds through. Like you the WaPo ignoring or soft-pedaling Amazon stories.