Actually, what the essay proposes wouldn't result in ignoring it, it'd result in making it more obvious. The idea of trying to understand and/or address the rational reasons behind a seemingly racist behavior is the process of stripping excuses that a person might have.

But it's only when you look beyond just assuming "oh, they're racist", that this sort of process can begin. And, as linked and explained in the article, there's no guarantee that you actually understand what motivates a person, especially if you haven't tried (or been forced to).

If you actually read the essay, Scott says that we should seek to find the underlying causes of unconscious racism, and treat those. Most racism without intent means that, presented with a better option, people would choose to discriminate less.

What he didn't mention in this essay is institutional racism, which in his terms must be racism by consequence, because institutions don't have beliefs or motives. At least not in this context. Institutional racism is something that needs addressing, but it's not the same racism by motive, nor should we expect the same solutions to work.