Look at the exquisitely skilful, careful structure of this piece, the way it dances between its developing argument and its vivid concrete examples. Look at the semi-transparent fabric of reasonableness softening, but not extinguishing, the righteous anger. Look at the humour. Look at the precision of the word-choice and the careful crafting of the sentence structure.
I can only assume that when people say she doesn't write well, what they're referring to is the fact that she writes simply and clearly, using easy, familiar words that represent the way her characters think and speak. It's almost as though she were writing fiction about children for children. D'oh.
This, however, is non-fiction for grown-ups. Go and have a read.