What this article doesn’t tell you is that the manager for Mexico is a Colombian and that was a big reason for the criticism.
Fans complain that Osorio is too analytical — “Profesor” they call him, not entirely out of respect. They wave off the many teams Osorio has beaten as second rate, and fixate on the handful of games he has lost. Most of all, they complain that he is not Mexican.
https://www.nytimes.com/2018/06/17/sports/world-cup/mexico-juan-osorio.html