He is not run of the mill. In fact, he overcame a lot to get the level of recognition that he deserves.
I am particularly impressed that he overcame a highly disadvantaged youth as an immigrant kid growing up in the
Bedford-Stuyvesant neighborhood of New York. Bed-Sty was a pit, to put it mildly. A high school scholarship got him out of Bed-Sty and in short order he was president of the student body, editor of the student paper and was captain of the baseball, cross-country and championship basketball team.
You can read about his acclaimed work in the first link I provided.
NPR wants political correctless employees. They are not fair and balanced. Firing Williams, an exemplar for liberals and a personal role model of the highest order, is just another confirmation of this.