I don't have a problem with reasoned criticism. I do have a problem with relentless negativity, incessant complaining based on "he's doing it wrong because that's not the way I'd do it", and we're all doomed hysterics.
Is a really good player leaving a good thing, no. Does it rise to the level of this nonsense, no friggin' way.
Nobody is untouchable, but if the rule is you gotta pick a side without knowing any actual facts about discussions, practice, meetings, interpersonal dynamics, I'm going with the guy that has been here and proven he knows what he is doing over a freshmen.