Because it reflects the actual real sacrifice that veterans made for you and your freedom and for each other. It should also encourage others to never make those same mistakes. Too many people don't know what death is, real gritty war death, its not clutch your chest and give a dramatic speech. Its real, good people, dying. Sacfricing themselves for humanity. If more people saw how horrible death and violence were, there maybe less of it. Most WW2 vets saw unspeakable things and they resolved to living the rest of their lives in peace.
Unlike say Rambo in your avatar who just blows and tears people up for entertainment.