Share 'No disc brakes in the top 10 Elite Men's racers at Worlds 2013'

It is interesting that there were no disc brakes used on the bikes ridden by the top 10 Elite Men's racers at Worlds 2013 (that I could see). Do you think that it is because of weight; due to the disc pad problems seen in conditions at US Nationals this year; or just tradition: http://velonews.competitor.com/2012/11/news/top-cyclocross-pros-still-stick-in-the-muds-as-regards-disc-brakes_263893