It's more a fanbase opinion than anything else, Derke's departure was by mutual agreement, here's an itw response given to a French media

‘You felt it was no longer possible to win everything with Fnatic? Is that why you left?’

"There were other problems with Fnatic. It was my decision to leave, but there was a lot going on behind the scenes and it felt like there was going to be a change no matter what. And I had the feeling that by changing every single part of this team, it was going to lose its level... So I said to myself that if there had to be a departure, it might as well be my own, so that I could go somewhere else and build something new, rather than staying and having to start again from the bottom."

From what I understand fnatic wanted to make at least one change, Derke not seeing the point said even if it means benching someone do it with me.