Ignoring for a moment the other billion problems with the U.S.–Iran war, I think the Strait of Hormuz situation illustrates quite clearly why you don't want a bunch of yes-people to tell you what you want to hear.

Clearly someone at DoD had thought about this situation and could have foreseen it (because attacks on shipping there are not new) and yet that advice was not heeded without a reasonable plan to address it.

Now the strait is closed and it's everyone's problem.