The CCP was extremely brutal in how they came to power and how they have maintained power.
The CCP were the very authors of the sabotage behind the NanJing Massacre, to just name one. Tang Sheng Chih, who died with national honors from the CCP, was responsible for setting up the KMT and sabotaging them. The CCP and its spies, like Tang, were responsible for the deaths at NanJing. Why support such and action? If you are the CCP, and the KMT is in charge, and you want them to be unpopular, and you want their power, and you are trying to stir up the nation to anger in your behalf...why not? They did not care about any Chinese people. They only wanted power.
The CCP was on a mission to sabotage and bring down the KMT at any cost.
These things are some of the core issues at stake...