Dan Ariely — author, renowned behavioral scientist and now also Chief Behavioral Officer at Insurance startup Lemonade points out back in 2010 that consultants rely on their overdeveloped confidence in having the right answers — rather than offering a framework of experiments.
“Companies pay amazing amounts of money to get answers from consultants with overdeveloped confidence in their own intuition. .. Second, there’s the false sense of security that heeding experts provides. When we pay consultants, we get an answer from them and not a list of experiments to conduct.” — Dan Ariely, http://bit.ly/2iw8aT6
The latter being according to the Cynefin Framework by Dave Snowden, the only valid approach to solving problems in uncertain complex domains — which is where, I would argue, most customer opportunities reside.
In 2013 Christensen, Wang and Bever wrote Consulting On The Cusp Of Disruption, pointing out that the consulting industry is ripe for being disrupted (a fact us as consultant find hars to acknoweldge)