So one of the most gun-free societies on Earth sufferers a long chain of dictatorships. Film at 11.
There was one attempt at armed revolt when one town raided a military arsenal. They got a couple of thousand guns, and then they got crushed when the national army surrounded them. That an armed rebellion not much larger than the Branch Davidians at Waco fails is not only not a surprise, combined with the decades of dictatorship in an unarmed but otherwise functioning society, it does far more to confirm the pro-gun argument than refute it. The Korean military could concentrate on one town because no other Koreans were armed, and nobody could come to the towns aid because no other Koreans were armed.
Military officers who use coup d'etats do so because they know that nobody is going to stop them. If armed civilian unrest or mass protests didn't overthrow the previous junta, they're probably not going to overthrow the next. Public opinion is largely irrelevant in such places, because the outcome all depends on which generals can assert leadership of the military, and thus establish a monopoly of force.