The SecDef sets the agenda. There is a reason most of the senior officers who have been speaking out about him have been Army. His vision of a modern force overvalues air power. The buck stopped with him. Literally. The Army and Marines have had to make do with crumbs from the table, having to shuffle $$ away from acquisition in order to fund the fight. The AF hasn't had to make such sacrifices. Rummy is a great man who has done a lot of good. But he's not perfect.
Despite Rummy's faults, he still stands head-and-shoulders taller than Robert Strange McNamara, or the non-entities that served as SecDef for the Commander-in-Sleaze.