Tom Rosenstiel, director of the Washington, DC–based Project for Excellence in Journalism, says, "I don’t have a lot of patience for any media criticism that is based in ideology. Frankly, [for] reporters who cover the news business, it makes our lives more complicated."
In other words, I can't be bothered to actually see whether Media Matters is good so I'll just dismiss it based on its ideology. Of course, what this ignores is that a massive proportion of our media now is "based in ideology" and is largely ignored by the "serious" media critics who probably use the same excuse. For example, let's check out Project for Excellence 2005 State of the News Media report, focusing on the content analysis portion of the Radio section. They discuss NPR, Howard Stern, Sirius, XM, Air America, and MPR. Um, anything missing guys?
The "respectable" insider institutional journalism watchdogs dutifully ignored the rise of the conservative media for years, and now it effectively controls the rest of the media. For a variety of reasons the conservative media has the power to set the agenda and control the content. As Ann Coulter said, "we have the media now." And they still ignore it, not wishing to waste their beautiful minds on it.
(yes I'm affiliated with media matters, and no nothing on this blog reflects their views).