The problem with theory - it simplifies. And simplification is important because our brains just aren't big enough to grok all the complexity. But that doesn't mean that things aren't complex. And it doesn't mean that the simplifications necessary to formulate theory won't do unintended violence (the insistence that class conflict accounts for all conflict is what led someone whom I believe is honestly well-meaning to do and say things recently that are seriously wrong, and in ways that are harmful to himself and others).
It's all about complexity. And while I've butted heads with Rebecca over all manner of things over the years, in the post I linked, she illustrates this perfectly.
If you think your theories account for everything, you are wrong. Listen more.