Earlier quoted context omitted.
Applying those labels to people who are objectively and overtly acting that way is not the problem. The problem is that way too often people are assuming it's there. It's a presumption of intent, "racism is one possible explanation for your viewpoint, therefore I somehow /just know/ that you are a racist person". Example: every recent white-cop-shot-a-black-person incident in the U.S. Not only is there widespread ass…
Data on lifetime likelihood of death by cop in the US by ethnicity. https://www.pnas.org/content/116/34/16793 It's very evident the US has strong implicit biases just from the Justice system. We could also look at incarceration rates, or sentencing disparities by ethnicity. At some point saying "hey, we can't just _assume_ this is racist" _appears_ less like good faith debate and more like bad faith denialism.
That said, studies like the one you're citing appear to be flawed because they fail to account for rates of crime (especially violent crime) as well as socioeconomic factors. Correlation is not causation and all that.
(see e.g. https://www.wsj.com/articles/the-myth-of-systemic-police-rac...)