As my grandfather used to say of his time in the Army, you learn very quickly on a bad posting that the fish rots from the head down. General McChrystal is at the very least guilty of fostering a culture of disrespect for civilian authority among his staff, which is not something generals should do.
But in doing so it might be worth noting he is only reflecting our broader culture,1 in which we appear to have determined that military service is honorable and civil service is dishonorable. This was not always the case; the US military used fairly regularly to be regarded as a home of reprobates and jobbers of the worst sort. I’m not sure exactly when the shift began to happen, nor do I know of any scholarly work on the subject, but at an educated guess I would say it traces to the turn of the twentieth century, and the relative success of the Root reforms at professionalizing the military and the relative failure of contemporary progressive reforms at rooting business corruption out of civilian politics.
1Which doesn’t let him off the hook; the military are supposed to be better behaved than the broader culture.2
2And even in the broader culture Bud Light Lime is a vile decoction that all right-thinking people deplore.