Yes, Bush and Cheney were caught sitting on their hands on 9/11, having lowered the priority of anti-terrorism actions to the point that they never had a meeting with Richard Clarke, the administration's top person on terrorism. B & C were working on a missile defense system for the first 9 months of 2001, if I recall.
My biggest problem with Bush is the lying. Bush lied to gain political support for a war that wouldn't have been supported if the truth were told. We've read excerpts from the Oct 2002 NIE that says there was plenty of opposition within the intelligence community to the idea that Iraq had WMDs, yet Bush and company used absolute phrases in their speeches: "There can be no doubt ... We know for a fact ... It is certain ...", where the truth wouldn't have been persuasive.
Bush and his administration made statements they knew were false in order to gain political and popular support for a war that has taken the lives of over 1000 American soldiers and countless 1000s of Iraqis. Now with the publication of the ISG report, we know for certain that the statements were false. With the publication of parts of the NIE, we know they knew the statements were false at the time.
The same situation applies to Bush's other reasons for prosecuting the war: Iraq involvement in 9/11 -- false; Iraq threat to U.S. -- false; invasion of Iraq justified on human rights grounds -- false. (see Human Rights Watch for the justification for a war on human rights grounds).
They're batting 0 for 4.
For those who may think this is a lesser problem than some others, consider the 9th Commandment in the Old Testament: "Thou shall not bear false witness against thy neighbor".
About half of the voters didn't believe Bush's lies. The other half did. Now anyone with open eyes and ears knows they've been the victim of lies. President Bush has broken the trust of the American people. Because of this, he can no longer serve effectively. Witness the cries of "wag the dog" after the mid-summer orange alerts when Kerry was ahead in the polls. He's now "the little boy who cried wolf". We can't trust our President to tell us the truth, even when he is.