I can recall when Avedons' In The American West was first published. The reaction to those photographs, now considered by some (most, really) to be true masterpieces, was similiar to the reaction to the photos by Jill Greenberg. How could Avedon have exploited these poor people! He must be a mean and heartless man to take advantage of the homeless, the young, the stupid, etc. I understand that Greenbergs subjects are children, and that is obviously a factor..sorta kinda, really the kids were not actually harmed, and they were in the care of their parents.
In my view Greenberg's work fails in that her message is vague, although the photos, absent her claim of political protest, are quite striking. As in the case of Mann, Avedon, Mapplethorpe, and many others, posterity holds the key to the worth of Greenbergs work.