Why would it cause more controversy? Is being prejudiced about race somehow much worse than being prejudiced about ethnic background or cultures? Prejudice is prejudice.
Also:
"While the concepts of race and ethnicity are considered to be separate in contemporary
social science, the two terms have a long history of equivalence in both popular usage and older social science literature. "Ethnicity" is often used in a sense close to one traditionally attributed to "race": the division of human groups based on qualities assumed to be essential or innate to the group (e.g. shared ancestry or shared behavior). Therefore,
racism and
racial discrimination are often used to describe discrimination on an ethnic or cultural basis, independent of whether these differences are described as racial."
https://en.wikipedia.org/wiki/Racism