First off, I'm going to protect the guilty.
I'm reading a scholarly book by a couple of folks not in mass comm but who, as part of their study, include a massive content analysis of newspaper letters to the editor. It's an excellent book (so far), and there's nothing wrong with how they analyzed the letters. Again, I'm protecting the guilty, so I won't even name their academic discipline, but the underlying assumption in their work is people choose to publish letters to the editor, and there's no mention at all of the fact the editors decide what letters get published. Indeed, if you read the book, you get the sense the letters reflect people's opinions on a topic, as if by magic their letters automatically appear in the newspaper.
Given the nature of the study, this is kinda a big deal. As someone steeped in journalism, I am of course well aware of the somewhat screwy process involved in what letters get published, what letters get tossed, and what letters get pasted to the newsroom bulletin board for a good laugh.
Clearly, these two fine scholars -- and again, it's a damn good book -- are innocent of such newsroom experience. Someone should have caught this when the book was being proposed or vetted. Then again, it was probably someone in their discipline, with little news experience, who vetted it.