As one of many reasons for xenophobia and racism is the dehumanisation of people who are different, Detroit might help racists step in the shoes of marginalised groups and see how most of them are just victims of racist societies, kind of like a self-fulfilling prophecy.
The initial scene with Marcus is pretty powerful to show senseless violence against non-humans. Detroit continues to show how one can become human or become emotionally intelligent instead. Sadly most racists are human…
I get what you’re saying, but I doubt a racist lacking the empathy towards fellow humans will somehow develop empathy towards robots.