Just because you don't see people making powerful arguments to their political masters does not mean that such arguments are not being made, before officers then appear to look supportive of the political decision after it has been taken.
From my very limited exposure to really senior officers, I think that you have some very high calibre blokes at high level at the moment. There may be some yes men, too, of course, but I think we're being a bit harsh and over-cynical here.