The reason is that, no matter how good the story, lying to get it raises as many questions about journalists as their subjects.
And he proceeds to his next subject:
Why do journalists keep making political contributions?
which has this fascinating coda:
So, working undercover to get an accurate news story raises questions. And it's imperative that reporters keep their political positions a secret--that they lie to their readers, by omission, about their political views.
The news outlets that don't ban donations seem to regard them as a matter of personal preference, like joining the PTA. But they seriously underestimate the public distrust of journalists, which is only fueled by such practices. Those who work for opinion magazines or are employed as commentators have a stronger case that their views are no secret. But there is still an important distinction between rhetorically supporting a candidate and helping bankroll one.
The scorecard -- 125 of 144 donations to Democrats -- provides fresh ammunition to those who say the press has a liberal tilt. It's hard to argue you don't favor one party when you've just coughed up cash for that party.
In both cases, not in order to get the readership more information, but to get them less information, all in order to preserve people like Howie in their positions of august authority and cocktail weenie consumption.