I don't think anyone is under the illusion that Breitbart can be boycotted or shamed. The market they cater to lives in a pretty air-tight bubble, the same bubble which sustains Fox News/Drudge Report/Rush Limbaugh etc....
You say this like the left doesn't have its own in the NYT, CNN, ABC, NBC, Huff, Salon, etc... that's much more of an bubbled echo chamber. At least on the right they get bombarded with MSM daily... they just know its straight up corrupt.
The left has its own biases, but to equate it with the Fox News/Breitbart bubble is dishonest. To take science as an example, the left has its own set of denialists (ex: anti-vaccers, anti-GMO), but the left has plenty of people who push back against such science denialism. The Fox News/Breitbart bubble doesn't have any such checking mechanism. There's a reason why creationism is popular in the US.
Clickbait becomes pointless if all the ad networks ban them