Actually we've seen modern states trying to use the militia concept in the modern era, but it was in the 1940s in the form of the Opolochenie and the Volksturm, both of which were convincing arguments against repeating the experience. Untrained civilians in the age of modern mass firepower will be butchered in short order for no gain. In Tallyrand's words it's worse than a crime, it's a mistake.