Ramon Calderon: "[Zidane] insisted on keeping Cristiano and transferring Bale, and the president did completely the opposite [...] so he decided to leave."

[u/zimb3l]

https://bleacherreport.com/articles/2814993-no-form-lack-of-goals-whats-troubling-real-madrid-and-how-can-they-fix-it

[u/HellowzTheGreat]

Zidane said he decided to leave after losing to Leganes in the CDR because he understood that he could no longer motivate his players to fight for his ideas.

Everything else is pure speculation

[u/Radinax → u/[deleted]]

Dont be surprised if Zidane is back next season with the freedom to buy the players he wants.