It is talked about, but maybe not to the extent that it could be. For obvious historic reasons, race and class are highly correlated. I think this causes certain class issues to disguise as race issues and vice versa. To be clear, both kinds of discrimination exist, both are terrible. But people are sometimes bad at separating correlated variables intuitively. And, how do I put it, the social sciences don’t have the reputation to always use the most statistically sound methods.