Okay, I'm going to keep up my Marxist critique of this Marxist critique of OOO this way: the accusation that talking about hammers is fetishism is based on a kind of Romanticism, though I hesitate to use that term. Let's call it a narrative of authenticity. Some things are more real than others, namely (in this case) praxis, which has to do with humans.
What happened to the Lacanian Marxist view that humans and humanism are part of the problem, not the solution? Why this anthropocentric, eighteenth-century view of an intrinsic humanity (praxis) that is distorted by capital? Isn't that what Marx was combating, in the very place of his critique of fetishism?
So again, theologians, I accuse you of being the fetishists here. You attribute some special godlike power to human agency and you see the problem as the distortion of this power by capital. This is, on Marxism's own terms, just regression to Enlightenment philosophy, that is, capitalist ideology.