Jeez! Click the link before criticizing it. It's a primary source, an interview with Assange. It's not a wire reprint.
Because Assange made the claims on Fox News. This is the source.
Because the interview in question was conducted by Fox News.
and Fox News wouldn't run the interview if they didn't like the results, so in that sense they are biased, just like NPR,PBS,CNN,MSNBC and everybody else.