It does bring up usury, but only tangentially, and it assumes a specific theological interpretation of usury as exploiting the poor, without offering a hermeneutical justification for why he believes that.

I actually agree with him, that the prohibition against usury in the Bible should be interpreted as exploitatively lending to the poor for personal gain. But the book doesn't dive into why we believe what we believe and just makes the assumption that this is the correct interpretation.