The current thinking is that there is no way to understand history, or literature, or theology, or sociology without first noting the biases. It's all about power relationships and preserving status and perpetuating...stuff. I agree with that considerably, and my best evidence is the behavior of current academics. Few eras and classes have exemplified that as clearly as our current crop.
When people tell you the terrible motives of those they disagree with, it is wise to pay attention. They are describing, or predicting what they would do and what their motives would be if they had the power, the money, or the status. I have seen this come true in my lifetime.