Do most white people do these things? Of course not. But I would seriously doubt the word of any American who says they don't have any direct ancestors who were racist or at least stood by quietly and allowed racism to flourish. Every day, I see things that remind me that the history, culture and economics and sometimes even the very buildings that I walk through were built by a system that singled out one group of people for exploitation because of the color of their skin. When that horrifying system was finally overthrown, many Americans, including some of my own ancestors as well as the ancestors of many of the people on this bbs, still spent the next 140 years trying desperately to keep parts of it alive.
But this has nothing to do with being white.
I'm of Eastern European Jewish decent and am as pasty white as you can get. My ancestors were never singled out because of the color of their skin but as everyone is aware, that didn't stop us from being singled out. And therefore, I find the very term "white guilt" itself to make several offensive implications. I am very aware that people like were harshly oppressed and that there are people even now who would be happy to do it again. And it has absolutely nothing to do with the color of either mine nor anyone else's skin.
I feel the weight of history too. I am acutely aware that if I was born a mere 40 years earlier and across an ocean things would not be so rosey and that the color of my skin has little to do with that. And I find the implication that because my skin is of a most pasty complexion that I must therefore have no personal or direct experience as to what it's like to be an oppressed minority fairly distressing.
OTOH, I know that this is not anyone's intent. Certainly no one in this thread or the author of the original article. But the term itself uses a level of granularity so huge as to miss the complexity involved in humans oppressing other humans throughout history. And by doing so, I feel it misses the point greatly. Could there be something akin to "imperialism guilt" on a societal level? I could buy that, I suppose... but none of it is caused by virtue of skin color which is practically incidental.