Because she spoke her mind in public, twice. If she wanted to truly help the Bush administration, she could do it in private communications.
As it is, she has given the MSM a club to beat Bush over the head with. Apparently, she either doesn't see it, or does see it, and doesn't care what effect it has.
Isn't a bit too much to expect from a columnist to restrict herself to private comments ? And besides, what is the points of having free and thriving Conservative media if the editors are only supposed to write what is approved by the White House ?
For example, many Conservatives are very wary of President Bush's plan about illegal immigration. Are they supposed to support it publicly at every occasion and only whisper disapproval when nobody else can hear ?