In the US "what we pay them to do" is vernacular for "it's their assigned job" or "it's what we asked them to do". I admit it's a bit of a weird phrase but its not actually referring to money. To your point: if the claim is that we're asking our military or our intelligence agencies to do things that aren't effective, then let's have that debate. Nuclear force reduction and end illegal surveillance? Sure. Nuclear disarmament and shutting down our SIGINT mission? Not so much.