This attitude is destructive as it's making it so difficult for us to come to any agreement on what we accept as a trustworthy third-party. Where do we start to give people some benefit of the doubt? As it is, even "trust but verify" can appear impossible. I'm not advocating some "can't we all be friends" platitude. As a practical matter, how do we move forward from here?
Edit: minor wording changes to remove generalization and grammar improvement
There's no way to prove objectively which sources are better but we still have to make judgments. The judgment about Breitbart is not a difficult one.
Slate.com does not describe themselves as a news source, so apparently not. I've certainly never thought of them as informative.
I can't personally comment on Breitbart's content, but apparently a number of their employees quit earlier this year, believing that the site has lost its journalistic integrity since the death of Andrew Breitbart.
https://www.washingtonpost.com/news/the-fix/wp/2014/10/21/le...
Time to update my news reading preferences!
edit: I suppose there might be a selection effect. The large networks are watched by everyone, and the smaller ones are sought out.
Is news.ycombinator.com a "real news source"? Should it be renamed to "notnews.ycombinator.com" or such?
Who decides what is and isn't a "real news source"?
Perhaps the judgement:
"breitbart.com is not a real news source."
is an example why so many people were astonished at the election results. After all, if you only talk to people who agree with you then you'll certainly be unaware of those who don't. And when there's a vote, you'll really be surprised!