I had missed this when I wrote my post making the same point.
I do think the reasons for the consensus (the conditions that trigger it) are not clear -- unless it is simply Marx's point that the will of the capitalist is to reduce wages as much as is possible, and the question is not that drive but what are the limits on that power. Marx seems to think the only limit is us! If we (workers) don't limit that power, there is no end to the degradation we will experience.
Carrol