Yes, it's useful. And yet, while other politicians may play to voter emotions by omitting costs and expected consequences of warfare, it might also be a PR device to be vocal about the _presence_ of such consequences. A lot of us respond positively to a leader mentioning the other side of the coin; it lends credibility, trustworthiness, and other supportive emotions. For the fact that it's an emotional component, it can be exploited as part of a political PR toolkit. It's not like the population (including some of us in this thread) will want anything more than a fleeting admission of what's really obvious anyway - that war is, to a significant extent, is indiscriminate; also harms bystanders or ourselves; that there are things that are hard to model, predict or foresee.
It would be equally impossible for a government to fully engage the population in the outcome estimation process, because that would by definition reveal critical information for the adversary which then would shift the odds, rendering the estimation overly optimistic, not to mention cutting the tree under yourself while giving questionable benefit.