Your comments appear to be prejudiced. I believe this tendency is a characteristic that can be observed in all human societies. People have a tendency to protect their own weaknesses. They are so fearful of acknowledging their flaws that they resort to accusing others of having those same flaws in order to reassure themselves. Additionally, they may feel so insecure that they cannot tolerate seeing others succeed. Insecure individuals often withhold compliments because they fear that others may surpass their own abilities, causing them to be left behind. Another possible reason for this behavior is that they have not accomplished much in their own lives, so they seek meaningless victories through the pleasure derived from humiliating someone else. It is also likely that they possess very low self-esteem. When they witness someone achieving something they themselves couldn't, they become envious, and the only way they can feel good about themselves is by belittling others.
Are you confident that this is a value system exclusive to the typical Chinese? Your comments appear to be prejudiced. I suggest you conduct your own research in google. I think the tendency to resent others' achievements and mock their downfalls is a universal trait across human societies.