All humans belong to the human race, so how can there be any racism. The term could be seen to imply that any particular 'race' is not human.

I thought that is what you meant, but the term is commonly known as prejudice against another person because of their color or physical features. It's a form of tribalism and has no logical basis. We have to separate that from cultural differences. Putting bigotry aside for cultural differences, which is also illogical, it is OK to disapprove of cultural practices which are cruel to animals, destroy the planet, or which violate human rights. That is a far cry from preventing someone from working or having a job because of their color, but some will call condemnation of cultural/religious practices as racism, and they are incorrect.