This is inevitable, because the whole purpose of leftism was to push a set of ethics and underlying heuristic assumptions about the nature of reality that is so completely wrong that it causes disfunction and weakness within any society that adopts these beliefs. An the reason why it was pushed in white societies was to weaken white societies enough to be push under by other ethnic groups.
It wasn't just particularly progressivism/SJW cultural marxism, the whole of leftism was set for this purpose. Liberalism, Democratic Socialism, Jacobinism… any early form of leftism was built to bait white people into this false system of beliefs. It sold itself a call for liberation from illegitimate, oppressive controls from the naturally hierarchical systems of Monarchy and Aristocracies. When it came to universal suffrage and democracy, it sold itself as a corrective shift in balance for the people, to manage their life as much as they can.
They used Emancipation and Civil Rights (especially in America) as a call to end the strife within the society via racial lines, and they sold it as a corrective shift towards a racially neutral, peaceful society. And the major component to that is being racially blind. Whites adopted it because they have been so thoroughly transformed intellectually by leftism. Other minorities, on the whole, were spared this indoctrination in which they kept a strong racial identity and where kept the ability to openly organize politically for the purpose of serving their own racial interests. This was kept somewhat subvertly for a long while, while white people were taught further to distance themselves from their white identity as they were continued to be sold this lie of a transformation into a racially neutral egalitarian ideal society. Its to the point where white Americans have lost all ethnic identity and connected with the greater cultural sphere of Europe overall (through public schools). Similar thing happened to Europeans as well through their own indoctrination via public schools.
As we come up to the millennium, left "liberalism" begins to die away, and the underlying festering infection has grown to be a overtly Progressive and Marxist driven left. The peaceful, cooperative, racial blind, and egalitarian society that the left liberals promised was a lie, a trap for white people to let their guard down for. The rise in anti-white marxism (which started its gradual progress since the 60's as least) has reached critical mass within the last decade, and white people see it as that moment where the trap is sprung and the long knifes are being unsheathed. SJWs are the malicious face underneath the mask of good natured egalitarianism and they now openly call for the extermination of white people and white culture.
Since white people are now seeing that the racially neutral, equal and fair promise as bullshit, and that they see these minorities coming in their country, using the democratic system put into place by leftists, to vote for their own racial interests over the interests of the native whites, whites are starting to wonder "why not us too?…". You see white people showing interests again in their history, their philosophy, their traditions as a way of pushing back against degenerate modern culture. You see white people question the nature of society, away from leftists virtues, and towards ideas of what benefits them and their people in the short and long run. You see white people organizing politically and not being afraid by the shame of leftists by their false system of morals. White people are waking up to the trap that they fell for, and are mobilizing to hit back, and hard.
