>>2717292well, yes.
first things first, making your work public has nothing to do with making yourself, and even less with making yourself rich.
then, what I criticize as taking advantage, in the case of sally mann, is that her oeuvre is, allegedly, of personal importance, of a intimate beauty. I guess this does not necessarily incurs in self promotion, as by art galleries, art museums and such. in his book, tarkovsky wrote some beautiful words on the matter of humbleness and anonymity of the artist; that the sense of beauty we perceive in gothic cathedrals are not linked with its author persona, as we link today, afterwards modernism, but with something both deeper and higher. but in anyway I'm condemn her work or her persona, I'm rather trying to answer you according to the question.
when the matter is exploitation by photodocumentarist, one got to be a bit more sensible and a bit more critical. of course sebastião salgado done a great work of presenting the state of hunger and misery in many regions of the earth. but, on his own region, he didn't even keep the revenues from his pictures to himself, rather publicized and donated to an organization (MST) directly linked to the greatest paramilitary organization on latin america, which is highly envolved in drug traffic etc (FARC). one might say this question barely touches his photography, and its true; but having he publicized himself as foreman of social and political questions of our time, especially on the third world, one can't help but notice this contradiction, in the way that by his pictures he advocates attention, but by his presentations and seminars, he acts in the reverse direction. this is an example of why I'm suspicious when the matter is big photodocumentarism.
there's a whole lot that could be said about the ethics of photodocumentarism, and there's also a documentary where don mcculin himself talks briefly on the matter -- highly recommended.