It's a very contrast of display thing I think. I've seen those sort of pages on a Macbook and they are more easily readable than they are on my machine, for instance. I have to use stylebot to 'fix' quite a few pages that commit this sin (to varying degrees). This is quite an extreme example though.
The body text is as close to black as it is white. #444 is borderline acceptable. #888 is absurd.