:Again, WP:Biased only applies to reliable sources and doesn't apply to questionable source. You seemed to miss from your quoting of WP:Biased "When dealing with a potentially biased source, editors should consider whether the source meets the normal requirements for reliable sources, such as editorial control and a reputation for fact-checking." Multiple other noticeboard discussions about Breitbart.com have concluded that it is not a reliable source for those very same reasons and others. WP:RSopinion speaks to sources that can be considered reliable for their author's opinion, which would make them a primary source for their author's opinion. The primary source for a Shaprio quote has no relevance to this article about a film. The only primary sources relevant to this article would be sources directly written by the director, the script, or things of that nature. Yes, just about anything can be used as a reliable primary source, that doesn't mean it's reliable for inclusion into articles that aren't about that specific source or its author. That's part of the reason why we don't take tweets from Ken Hamm and include them on the article about Global Climate Change. 

 :Lastly, as per WP:Questionable "Questionable sources are generally unsuitable for citing contentious claims about third parties, which includes claims against institutions, persons living or dead, as well as more ill-defined entities. The proper uses of a questionable source are very limited." This specifically says that even when citing a questionable source, it is unsuitable for making contentious claims about third parties and more ill-defined entities. The entities don't have to be well defined, they can be ill-defined and Shapiro's criticisms of leftist critics would be included as ill-defined third parties/entities. Furthermore, it says that the use of questionable sources are very limited. This is the opposite of trying to include questionable sources wherever you want so long as you attribute it. That wouldn't be very limited at all. Luckily, multiple policies clearly express how questionable source are limited and how they can be used. They should only be used in articles about themselves or authors and can't be used to make contentious claims about others.