I'd actually recommend Marx if you want to genuinely understand the ideology and why it appeals to people. I'm not saying I agree with him. I'm just saying a lot of what people label as communist is just some authoritarian assholery. If communism is really so terrible, we should be able to read what Marx said and clearly see the flaws in it, right? 

 A shortcut would be to simply ask, "Does this ideology respect the life, liberty, and property of the individual?" 

 And how do you propose to answer that question? By what definition and where did it come from? 

 Do you want your life, liberty, and property respected? Who owns you?