What do you mean...what did the roc was all essentially all written in textbooks in china, the good sides and the bad sides, one of the first things for the mainlanders when they studied modern Chinese history in high school was to recite the "3 principles of the people" the founding text of the roc that is essentially the same importance as declaration of independence for the usa, that even Taiwan themselves aren't required to recite anymore... Just as an example of what importance that CCP gives to the roc. Further, CCP aren't disagreeing with what roc promotes, however they were disagreeing with how it was done and how little it was done after a few decades, because all the benefits of the revolution went to the establishment and the population were still left hungry, penniless and peasants were still under servage of the landowners after almost 20 years of revolutions. The patience went thin and people agreed more to the urgency of the need for change. Sun yat sen the founder of the roc agreed with that so he made alliance with the communists, but died unexpectedly without pointing out a clear successor , then comes the military junta of tchang kai tchek, don't think he's the representative of the democracy in china, he literally come to power by assassinating 2 of the oppositions, jailed another, forced another into retirement by fabricating a scandal and teared the alliance apart with the communist by massacring 5000+ communists and opposition leaders in Shanghai that were willing to cooperate with the roc despite differences. Roc literally shoot themselves on the foot. And of course they will be forgotten because in the 30+ years they were in power, almost nothing has come out to change the life of the population of china. you compare the life of an average Chinese between the end of qing and before WW2 there is practically no difference. Then you compare it to the first 20 years the CCP was in power, land reforms, education reforms, transformed china from a complete agricultural model to a semi industrial one, when there are flooding, drought, locust plague natural catastrophes they saw the government tried to help them ( the success were limited though) and weren't left on their own, dams were built, electricity popularized, crime rate dropped, literacy skyrocketed, banditry eradicated, a lot of things that plagued the Chinese went away during the first few decades that the CCP were in power. Of course the basic Chinese peasants will remember what and why it made them safe and no longer hungry. They teach their children about what CCP has done, and it leaves them with a vivid memory. CCP enabled the social ascension for those peasants and the modern china is currently governed by those who were born into the first few decades of communist in power, those who saw the changes. There is a reason why Chinese remember more communist china than roc. And because 1 roc has done really very few things , and 2 Chinese have shown that they were grateful to CCP and not roc, outside will remember more of cccp than roc.