Why liberals don't want to call it class warfare
During the mid 1800's Karl Marx noted in his communist manifesto that classes eventually emerge out of capitalist societies.
As this division between classes grew Marx saw that criticizing the system would be an opportunistic platform to trigger war between those who were successful in society and those who were not. The motto that he coined was' "workers of the world unite"
For many decades Communists were under the assumption that eventually every major society would fall into a system of communism or socialism. To them it was a scientific fact. Unfortunately for them, when a war did come, the only place where this idea of communism took root in was Russia which was hardly an industrialized nation.
It was at that point after the first world war when the failure of this guaranteed prognostication of the most intelligent communist economists was realized, and they needed to attach Marxism to another system, a cultural system. And thus cultural Marxism was born.
The perpetrators of Cultural Marxism eventually set up shop in America at Columbia University where they applied critical theory to American culture in an attempt to demoralize our values in order to insert their own ideology which is opposite to what was previously taught.
Since then the trend of criticizing America for anything and everything that it has accomplished has been a topic of discussion in our institutions. So when your children come home from school as blazing liberals who hate America, it isn't hard to see where it all came from.
The biggest part of the indoctrination process is to convince our youth that the old people are senile bigots who cling to crazy outdated ideas that have unequivocally been debunked long ago, and the mistakes made in the past by previous generations of Marxists, communists, and socialists have all been learned and disposed of.
The goal now is to disassociate the previous ruthless dictators of socialist and communist countries with the "true" premises of communism and socialism. To the intellectuals who preach these ideologies it's simply not fair to compare them to Stalin, Castro, Kim Jong Ill, Mao, and Che Gueverra because those guys never really gave true communism a chance.
The truth which is stareing the rest of us in the face is that communism and socialism always end the same way, millions of people get murdered at the emergence of a ruthless dictator. So when the OWS movement emerged they came up with something a little more palatable than those nasty old commie slogans like "workers unite", and "class warfare", because that would be too obvious. It's better for them to just "eat the rich" because that couldn't possibly have anything to do with communism.