Systemic reasons are why it's common to see the collective responsible for the systemic patterns in society be so fervent to deny systemic issues exist.
I myself like the idea of my success being attributed to my hard work. I would like to think that I bootstrapped my way to success. It's not an easy feeling to accept that in many ways by virtue of just being part of the main majority collective I by default have an advantage in my community over those that aren't a member in that majority collective group.
i.e. if the majority % of users in a forum are belonging to a certain category then it's reasonable to believe that most of that majority would be against anything perceived as a criticism of their group (and by extension themselves).
American's love talking about those issues. It's probably the biggest thing they love talking about compared to most other countries.