Comment by gcanyon

This jumped out at me as well. I think it's fair to say that if you aggregate all predictions, there will be those who vastly over- and under-estimate progress on any given time frame, so depending on who the authors were paying attention to, both could be correct. The interesting question is whether there is, in aggregate, a tendency to over- or under-estimate on a given time frame. My money is on Amara's Law for that.