I think you are talking about something different. The parent is saying that little-r racism isn't the result of one single person deliberately trying to be racist towards someone, it's the aggregate of things people do collectively without thinking about it that are racist. For example, someone named DeQuan is less likely to get an interview callback compared to John, even if they have the same resumes. Or instead, a black teenager is a lot more likely to have the cops called on him for walking down the street in a residential area than a white teenager. It has less to do with intention and more to do with implicit biases that collectively result in systemic discrimination