Deborah Tannen wrote The Argument Culture as a response to what she felt was the increasingly vitriolic state of dialogue in the United States. Her main point is that it has become impossible to actually have a dialogue on an issue because of the loud, dissenting voices on either side.
The state of dialogue in the U.S. has changed dramatically in the fourteen years since Tannen wrote the book. The major portion of radio, television, and internet dialogue today is focused entirely on pushing one point of view, and disproving all others; many of them engage in outright fabrication in the knowledge that public culture will pick up on a sensational story and ignore the correction that might be printed later.
In this sense, Tannen's main point is still correct. With almost all dialogues today "frame[d] all issues in terms of diametrically opposed sides...the quality of information received is compromised" (eNotes Salem). Instead of focusing on issues, people tend to follow the media and focus on "sides," which damages their ability to listen objectively, and damages the credibility of those who debate; the objective dialogue is drowned out by the sensationalism.