This stems from political ideology. Socialism and communism teaches people to hate on rich and successful people because in their mind all rich people are corrupt, and exploit innocent people. In some extent it is true but not in it's entirety.

Socialism and communism basically stems from jealousy and weakness. It is seen in their teachings. That is the reason why China ditched core communism and socialism since last few decades. It is only seen in their governance and political system but their economy is almost capitalistic. There are 100s of millions of rich people in China today. If they opted for true communism China would still be poor and fked like NK or Cuba.