James has now argued from Jesus and from theology. He now argues from sheer pragmatics that despising the poor is stupid:

Is it not the rich who are exploiting you? Are they not the ones who are dragging you into court? (James 2:6-7)

The setting has shifted to the realities of the experiences of the poor.

The poor had no recourse. The poor lived from hand to mouth. The poor were being dragged, unjustly, into court. The rich, who had plenty and who had power, were dragging the poor into court. There they were extracting even more out of them and there they were sending them off to prisons. There the rich were using their power to exploit the poor.

Incredibly, the messianists were both poor and kow-towing to the rich, the very persons who were exploiting their fellow poor. It makes absolutely no sense, James is telling his readers.