Probably because the media/pundits/Beltway insiders tend to be upscale whites. Once in college I had a roommate who was black and from a well-to-do family and he would complain incessantly about how "ghetto" some of the black people in the city we went to school in were. Racial groups tend to project criticism inward onto their "inferior" group members.
A lot of the conflicted feelings upscale white liberals tend to have towards those people stem from the fact that the mere existence of white people who are poor and disadvantaged kind of throws a wrench into their notion of racial power dynamics trumping everything else. There's this sense of, "But you don't have an excuse for being poor. You're white!"
It's more that blacks from better backgrounds are worried that their ghetto counterparts are making
all of them look bad. Nobody looks at Kid Rock and says "Gee, white people sure are trashy." It's a completely different thing as a minority.
And liberals can make an excuse for anything. We always blame everybody but the poor person for his poverty
