They present the non military side advice which should very much be presented to decision maker for better informed decision. They also help minister in seeing thru some tricks employed to force the hand, similarly army too call out BS and cost of inaction.I think the issue here is the quality of advice they offer & not the decisions to be taken which in any case is not theirs to make. For further clarity, Imagine for a moment, you're held accountable for issues over which you have no decision making powers except for an advisory role & executive capacity for decisions taken elsewhere. How exactly would you behave?
Army thinks in particular way, from security point of view and that's from where they present their options and proposals. No doubt it's for better security of nation but we have to select what we can pick due to scarcity of resources, that's where they come.