The concept of a press corps that strives for objectivity and hews to rigorous standards of conduct is a product of the Progressive Era. Unsurprisingly, especially in an era when large segments of the conservative movement have come to regard the Progressive Era as the root of all evil, not everybody agrees with this ideal. This is one of the dynamics that's emerged from the latest Breitbart scandal. You have figures like Rush Limbaugh rallying around Breitbart. Or James Taranto arguing that the real villain here is the NAACP:
Are we to believe that Ben Jealous thought Breitbart was what Dan Rather, before his fall, claimed to be--an impartial and reliable purveyor of facts? In the unlikely event that the answer to that question is yes, doesn't his failure to know better reflect a stunning incompetence?
(David Frum wittily summarizes Taranto's argument: As Otter says in Animal House: “You fucked up. You trusted us.”)
A couple days ago, National Review's Kevin Williamson argued that Breitbart has higher standards than the mainstream media, because Breitbart expressed regret and Dan Rather didn't. I noted that Breitbart did not apologize at all, and Dan Rather and his producer lost their jobs. Williamson replies by changing the subject to my description of Breitbart having committed a "malicious error," which he disputes. I think it's a fair description given Breitbart's history of such errors, but it's beside the point.
The point is that news organizations that hew to accepted journalism standards may make mistakes, but they apologize for those mistakes and take steps to ensure that they don't recur. Breitbart has done no such thing. And why should he? With so many conservatives rallying around him, he has no reason to change his ways.
None of this is to say that conservatives can't hold themselves to high journalistic standards. Many of them do. But it shouldn't come as any surprise that many members of a movement that despises the ethos of progressivism -- elites using rigorous methods to determine some objective reality in order to advance the public good -- also despise its application to journalism.