i think it’s more that they think they’re being asked to apologize for benefiting from systemic racism rather than being asked to acknowledge and correct it. if systemic racism is real then it means that all their success is tainted and fake, and since their social and economic status forms the basis of their self-identity, it reads to them as an attack on the validity of their own self-image. so, since they’re racist they try to make it about their race instead of their racism.