McKinsey has many controversies. [1]
McKinsey and Jeff Skilling used Enron as a "sandbox". [2]
McKinsey is somewhat a consult cult that ruined agility with "Agile" which goes against everything agile was supposed to be. [3] Real agile and agility is now crushed due to them turning it into a micromanagement always on critical path. [4]
McKinsey margin cutting has killed off lots of research and development and innovation.
[1] https://en.wikipedia.org/wiki/McKinsey_%26_Company#Controver...
[2] https://en.wikipedia.org/wiki/McKinsey_%26_Company#Enron