Co-sign on the underlying question here, a leftover of last year's teaching. The lack of interest in justice is only partly explanatory of the reasons feminism and racism tend to get short shrift compared to LGBT questions. Let me suggest another possibility: if the relevant category is 'fairness,' there was something patently unfair in the treatment of that group of people which cannot (in the minds of students) be attributed to anything but animus. However, students tend also to be of the belief that the ultimate explanations for things lay in 'science.' No one will dispute the biological differences between men and women, and so there's a reluctance to believe that social roles are entirely determined by society. Feminism, in other words, is nice and all, but since only women can have babies, we can never dismiss the possibility that womens' difficulty in achieving social and political equality has something to do with biology.
The interest in evolutionary biology doesn't help: here it's apposite to note that the most susceptible audience for big, poorly sourced 'explain it all' non-fiction books are high schoolers who like the air of sophistication and can't notice the problems with the argument. Steven Pinker knows very little about the social sciences, but you'd never know it to talk to them.
The same also with race: students tend to think that all people should be treated equally, but seem fuzzy on whether all people are actually equal. (If you were so inclined and wanted to look for a place where the dearth of religious education negatively affects the young, the inability to recognize that the equality of people is a moral facet independent of any physical or mental characteristics would be it. Judaism and Christianity are quite clear that the equal status of persons has little to do with anything tangible about those persons.)