I'm the guy who currently wears a uniform that is being phased out. Even when I get issued my new boots, I have made it clear that I will continue wearing the old one until they are officially phased out. There's a lot of people like me in the Guard, which is a relaxed environment compared to Active Duty. On a more serious level, consider how many members of the armed forces would fight the government if it ever ordered us to turn on the people. We are citizen soldiers who vote and discuss politics in the break room.
Note that Billy, a young vet, and me, a service member ripped McChrystal to pieces for being a retard. All of his support comes from civillians, just like MacArthur and his tinkertape parades and whatnot.
Psychologically, its easy to drop bombs from 20,000 feet. Its difficult to bring the reality of this to a pilot, but considering that Tibbets got to see much coverage of his actions and still supported them, I think you have your answer.
If you think that an obliterated Japan, occupied in the north by fucking Soviets and a communist puppet regime, and a south that would be incapable of economic recovery and unwilling to ever reach out again to the US for a bloody massacre of an invasion would have been better for the Japanese, I'm just going to assume you never considered this situation, or you just don't care, because atomic weapons are evil.
In matters other than policy, there's plenty of room for voicing dissent. In terms of military policy, you can always utilize the chain of command for disagreements. My unit created an absolutely retarded schedule for the active forces a couple of years ago. Now the schedule has reverted back to mostly the old one but with accomodations for people who can manage an alternate one. It got changed because people were very vocal through the chain of command that they were underwhelmed.
Sure, if they fuck up, you'll hear people all throughout the military calling them retards, but they still can't publish those sentiments like McChrystal did of Obama. If one were in a position to talk to Patraeus, and they actually understood field tactics and strategy, I'm sure if they explained their vision to him and were polite, he'd let them talk about it.