"And has anyone actually ever taken the trouble to identify the criteria for "secretive" and do a real comparison of administrations?"
Aftering witnessing the meltdown from the Cheney incident, it is obvious that the media associates "secretive" with any information that they are not immediately privy to.
The simple fact is, the media thinks this administration is secretive because they are not allowed the same access and preferential treatment they received from the Clintons. Unlike the Clinton's, Bush has never been concerned with managing the news cycles, thus, he didn't want or need spin-meisters out there rubbing elbows with pubishers in an attempt to manage...or massage, the news (and egos).
While this may be regretable in some regards, it was obvious that the media's hostility was not going to let this happen regardless of what the Administration did. Thus, the media's role in Washington is less significant as the President doesn't go through the media, but rather over and around them.
This is especially ironic when you consider that while Clinton may have been jovial with the media, he lied to them as often as he did everyone else. Yet, because he and the media had a shared ideological agenda, his "secretive" and manipulative administration was tolerable for the greater cause. Bush has made the media less relevant...and in many cases, look like fools. Bottom line: They hate him.