I have politely declined to give a detailed answer to that question, even though I find the psychology of it fascinating.
I have not said "Nesta sucks" or "Nesta rules". I have not opined on whether his on-field performance (past or future) merits his retention. I have simply been a messenger for a factual occurrence (Nesta was told that he was free to leave) that is a non-opinion type of a thing (although I guess that Nesta could convince himself that he has an opinion that he was not asked to leave).
And rather than simply accepting a somewhat unfortunate turn of events, certain Nesta-truthers are looking for any and every reason to deny what actually happened. People who convey what happened are questioned and challenged and mocked. We are told "this doesn't make sense" and "it couldn't have possibly happened that way". We are told that nobody in his/her right mind would believe this.
But...why?
Do any of the doubters have some independent source, like a player, who has told him "nah, man, Nesta has been planning this for a while, it was all him, it was by his own choice"? Nope (although now that I've mentioned it, I'm sure a couple of jokesters are going to claim fake inside information).
I realize that Nesta has fans. ****, I've been a fan of his the entire time. I have also felt that he has not played to his full potential. Both thoughts can coexist in one person's head at the same time. I have hoped that Nesta's passion would translate into leadership and guidance that would elevate the play of his teammates. I hope that it will in the future.
Every player who has put up stats at UM (as long as the entire statline wasn't penalties, drops, and/or missed tackles) represents an immediate loss to the team, as a player, as "depth", as experience, as a teammate. Nesta will need to be replaced. We may not have his replacement on the roster today.
But I'm quite certain that Mario realizes that too, and did not simply dismiss Nesta because he wore a hat inside the building or some such nonsense. Too many people are trying to make this all about on-field performance, but it's not that.
Someday, the Nesta-truthers will have some perspective on this. Until then, feel free to believe what you want to believe.