These are organs of world government coming into being. Imperfectly of course, and stained from the tortuous processes of their birth.
It may be right tactically to oppose them, but that action too is part of the process of them being shaped as accountable organs of world government.
Pure opposition as a matter of principle is leftist gesture politics. IMHO of course.
The most revolutionary stance is to calculate what reforms are most in the interests of the people of the world and which can be accomplished in the next three years, in the three years after that, and the three years after that.
However passionately leftists may denounce the IMF, its members will not suffer a painful death. Nor should they necessarily: they are merely the personifications of abstract global capital.
The tactical reality is that on the eve of the triumph of the world revolution, they will be offered early retirement.
So intelligent revolutionary reforms please, not gesture leftism.