In vanilla Civilization VI and Rise and Fall, this policy isn't worth adopting unless you're fighting for survival and war weariness has put your cities at risk of revolting. It's better in Gathering Storm, in which its added Production bonuses for Supply Convoys, Drones, Anti-Air Guns, and Mobile SAMs (all inherited from Patriotic War) will help you prepare to launch a counteroffensive as you beat the enemy back.
Civilopedia entry Edit
Although the term “Motherland” has been adopted by a number of groups to refer to their homeland, it is most closely associated with Soviet Russia and especially the defense of Russia against the Nazi German invasion during World War II. During the course of that struggle, Russia lost some 26.6 million people, 16 million of them civilians – roughly 13.7% of its 1940 population. The spirit of defiance and extreme sacrifice by the common people against foreign invasion is credited with the victory, for there certainly was little love for the brutal Soviet regime itself among them. These days, in Russia 23 February has been set aside as “Defense of the Motherland Day.” Less bloodily, in the late 1800s the Indian nationalist movement referred to their homeland as 'Bharat Mata' (Mother India) with no sacrifice too great for her freedom.