Well many in my family have this sort of grudge against the USSR and Nazi Germany, mostly because one of my grandfathers fled in haste from Soviet Occupation after WWII and his relatives suffered from persecution just as much as they did under the previous regime. It's something that made such a wide impact on the world that no wonder 80% of the guys you will talk to had some distant relative involved with it. And popular resentments can prevail for centuries.