We can only guess: 1 - Supervisors might feel threatened or disrespected 2 - https://en.wikipedia.org/wiki/Illusory_superiority https://en.wikipedia.org/wiki/

We can only guess: 1 - Supervisors might feel threatened or disrespected 2 - https://en.wikipedia.org/wiki/Illusory_superiority https://en.wikipedia.org/wiki/Illusory_superiority 3 - Cost (with or without considering the true value/cost)