For a lot of white people, white guilt is a form of strategic self-deprecation. People typically self-deprecate in order to assuage the competitive concerns of others. Most of the time it is ironic; we don’t actually think poorly of ourselves, but we joke about it to put others at ease.

On a surface level, we’re communicating to others that we won’t be aggressive assholes. Maybe we’re lying, maybe not. But the display usually fosters better cooperation, which is both desirable and powerful… in a homogeneous high-trust society where such gestures are reciprocated.

In a multicultural low-trust society, self-deprecation is tantamount to showing a predatory your belly. And racial self-deprecation communicates to everyone that should any type of competition arise, you won’t be consolidating influence or power with your own racial cohort - not even if every other racial cohort explicitly does so.

It’s worth noting that some low value cultures view any self-deprecation is weakness. These cultures tend to be low in cooperation, which also means they tend to be low in achievement/advancement. Most of Africa is still a primitive shithole because the people who live there are incapable of sustained cooperation.