Only people who are priviledged think everything in the world is just fine. There is plenty of injustice in the world. There are many marginalized and voiceless people who deserve better. There is reason to be morally outraged, and we should do what we can to oppose the injustices. Observations can be unreliable.
Naive realism is untenable.
We do not observe the world directly. Our observations are colored by our sensory systems. Note that criticisms of naive realism did not originate with Postmodernism. Plato identified the problem with observation in his allegory regarding shadows on cave walls. Modern arguments against naive realism can be found in the philosophy of science literature.