I have been thinking about how to more fully respond to this, off and on for the past couple days. I didn't just want to be snarky, and give you a serious response, because I think you're being earnest, and you're not a horrible monster like Essay.
what you say here is obvious and true. the movie was about the "soft" racism of liberal whites. anybody who didn't get that must have been stone drunk when watching or mentally disabled - they certainly were not subtle about what they were trying to say. but that idea, that truth, doesn't make a good movie. the idea was clever, the execution was lacking. the main character is a great actor, his episode of black mirror being the best of that show, but he was left with nothing to work with in this movie. i just didn't think it was any good.