Even if Bush was inclined to accept anybody elses opinion on this, he can't fire Rumsfeld now or he will look like Bush Sr. and "No new taxes." He has gone too far in saying Rumsfeld will stay to the end to back out now.
What I find more interesting is the near open revolt by the military. I have never seen anything close to this level of rejection by the US military. Even Clinton, who had a somewhat uncertain relation with the military, got more support. And the Bush administration was very popular with the military when they first came into power.
The active generals, staff and soldiers have been very careful careful in what they have said (and rightly so) but the unhappiness seems near universal. There are many countries where the military would have overthrown the government or the government would have sacked half the senior staff before now. Strong commitment to the principle of civilian control of the military but keeping civilians out of the operations of the military is one of the US's strengths.
I suspect that it is the bungling of this principle that is one of the things turning the military against the administration. From using mercenaries to meddling in military operations for political reasons, this administration has violated that principle deeply in many ways.
Jay