I don't find it hard to imagine, as there are plenty of privileged white people in the U.S. who barely ever come into contact with black people in a social context. So they just say the first thing that comes into their minds. They feel entitled to start that conversation and treat black people as instant free learning opportunities available any time in any context. It isn't always mean-spirited. It's just vastly ignorant. People can progress beyond it but I think that takes time, listening, education, and learning some personal humility which not everyone has motivation or necessity to develop.