Yes, I've read most of your links. If I missed something, you can always link it again.

(1) Tribalism is necessary but not sufficient for racism. Once you have racism, however, tribalism may (empirical question: is it?) be sufficient to sustain it.

(2) It is possible for racism to be initiated and maintained by different mechanisms. So if we're talking about racism now, that something was involved in its founding is not alone justification for it being the primary thing you care about.

(3) Inasmuch as Bell is a Critical Theorist (and, consistent with this, he calls for revolutionizing society), he's a far greater threat that King whose actual policy objectives, like universal basic income, would only substantially alter society. King was dangerous because of his appeal, not his ideas. Wall Street would rightfully be terrified of Bell if they thought he could have any real impact.