Tbh, the problem is just that white people are little kids who can't handle criticism. Sakai ends his book by saying:

The thesis we have advanced about the settleristic and non-proletarian nature of the U.S. oppressor nation is a historic truth, and thereby a key to leading the concrete struggles of today. Self-reliance and building mass institutions and movements of a specific national character, under the leadership of a communist party, are absolute necessities for the oppressed. Without these there can be no national liberation. This thesis is not “anti-white” or “racialist” or “narrow nationalism.” Rather, it is the advocates of oppressor nation hegemony over all struggles of the masses that are promoting the narrowest of nationalisms — that of the U.S. settler nation. When we say that the principal characteristic of imperialism is parasitism, we are also saying that the principal characteristic of settler trade unionism is parasitism, and that the principal characteristic of settler radicalism is parasitism.

Every nation and people has its own contribution to make to the world revolution. This is true for all of us, and obviously for Euro-Amerikans as well. But this is another discussion, one that can only really take place in the context of breaking up the U.S. Empire and ending the U.S. oppressor nation.

He EXPLICITLY states that his goal is using historical materialism to understand the failure of American communism, but readers don't like what history says about them and close their ears. This is why I personally don't have faith in them. But Sakai's thesis is not mine. He wants people to break the colonial state, and to do that you're going to need white people to become disillusioned and see it for what it is.

If you think that that disillusionment is anti-white, then you're basically admitting that white people and imperialism cannot be separated, and that you have to advocate keeping colonialism alive to avoid hurting their feelings.