The duty of a patriot is to speak out when you believe something is wrong. Agree or disagree, these men are expressing their sincere beliefs on the way the war is going. They have earned the right to do so, and they speak from experiences that the rest of us cannot begin to understand.
If those retired generals are really so troubled about the way Rumsfeld is running the war, they should get together and ask for a private meeting with the president to discuss their outrage and/or particular concerns. I'll concede they have earned the right to express their displeasure, but they chose a most unbecoming, unprofessional and disrespectful way in which to do so.