In my perception, the problem lies with lazy news corporations. They don't have specialist journalists or researchers any more, and throw together extremely badly researched stories. To gain any sense of credibility, they then wheel out a paid name who often compounds the rubbish. David Learmount and John Nichol are two good examples (the latter excelling himself on the first night of the second Gulf War, and Learmont's initial BBC interviews on the recent hijacking were pretty epic). The good commentators are rarely noticed, if used, as they don't give the punchy comments that the preferred "experts" give. Unfortunately, this means that the whole group's reputation is tarnished. Of course, the same is true of pundits in most fields of specialisation.