The experts in baseball for a long time thought baseball should be played a certain way. Bill James starting proposing radically different approaches that were later put into practice by Billy Beane (described in Moneyball) and later by Theo Epstein (who led the front office for the Red Sox and Cubs organizations when they won the World Series the article mentions). The story of baseball over the past 10-15 years has been about ignoring one set of experts as the industry has developed a new set of experts.
Another problem with experts I would have like to see this article address is when experts overstep their area of expertise. Experts can tell us facts from their area of expertise, but when we have complicated problems that involve trade-offs from areas outside the expert's area, that can lead to bad decisions.