The true reason behind White guilt
Ask yourself how come there is basically no White guilt relative to Asians? There are definitely some bad things Whites have done to Asians historically, and Chinese for example helped build the American railroads that connected the country. Yet almost no one is pushing White guilt towards Asians or the idea that "Asians built the country". How come?
Because Asians are successful and there is no need for that narrative of Asian victimhood. Blacks on the other hand are not, so they must push one sided, decontextualized and exaggerated narratives of White guilt and Black victimhood. (If Asians on the other hand had the same problems as Blacks, we wouldn't hear the end of how Whites treated Japanese Americans during WW2, how Chinese built the railroads and what the British Empire did to China during opium wars).
Liberals know that without that one sided narrative of White guilt towards Blacks, Whites might start judging Blacks according to their character, and that is unacceptable. (liberals are now openly saying this MLK standards is racist, ask yourself why)
White guilt isn't the result of White behaviour, it's a result of BLACK FAILURE. If Blacks in America were successful, NOBODY would be pushing White guilt today.
The fact Blacks are such miserable failures in America is already costing White people trillions, not to mention all the city destruction, crime, affirmative action etc. But as if that is not enough, now that Blacks have such problems, Whites have to be demonized on top of it just to fight potential resentment against Blacks which they bring to themselves with their behaviour.