I really think he's leaving. Or rather WANTING to leave. And most probably MAranello wants it too. At least both PR factories are spreading the expected rumours that seem to root the split.
Let's go by parts.
Alonso is a character by himself. Impossible to compare him with other stars. There's some kind of
epic that it's gonna happen with hime wherever he is, whatever he does. Not quite sure if that blossoms from himself or his environment... but anyway he choses his environment. It's a bit like Biaggi, in much a wide way to see it. Though at least Biaggi was funny in that clownish character he built.
Setup? who knows! I read the other view a former Renault's engineer (not sure if the same) in which I saw the opposite... or maybe the same? he said he addpated to car's pros and cons like nobody else. That's a praise, but yes it sets a patrh quite different to being a setup wizard. And then who was? Nowadays, who can? Schumi was quoted as that... but there's evidence that either he had lost it or there's no place for taht, today. Consider the way feedback and testing works today... Indeed it well seems he manages to set tha cars (or the teams) more to his liking than his eventual team mate.
I'd say that ANY team will be better with him than without him, in terms of driving, getting results, and
basta. Yes there's indeed a big question mark on him about team work "lubrication", and there's no particular evidence that he's a plus in terms or developement, neither a minus, of course.
But he can drive an F1 as fast as anyone and fight every mile of a GP.
Ferrari is no longer comfy with him because yes he can talk too much. And there seems to be the sensation that they are wasting his talents with poor cars. Kinda he puts them in evidence. True or not, but there's that feeling. As Alonzo Harris (he, funny coincidence) says in "Training day"
it's not what you know, it's what you can prove.
Alonso is tired of not having a good car. It's been 8 years without a title. He now knows he'll never be a 4 or 5 title holder which he most probably expected to be, and has seen one just getting there in front of his noses... and to his own damage: he lost two of those titles.
So what was his plan? wait and see, to an oportunity to materialise: empty place at Mercedes, maybe at Red Bull, propsects of a competitive McLaren (I'm sure Dennis would show him, in order to convince him, more data than usual secrecy would suggest) and jump by surprise... as he tried between 2013 and 2014. But Ferrari shake up, and some media buzz seem to have spoilt that plan.
After all, he's so convinced -
as a result of repeating it 10.000 times- that he can win the title with a car some 0,5 sec off the pace, he'll do the rest -
I don't remember any champion claiming that, at least so consistently... well bar Biaggi!- so what will happen?
If McLaren and Honda give enough warranties, he'll jump in there. And don't be too surprised if two important sponsors, both "red and white" jump together with him. McLaren sees too calm to having lost Vodafone, Johnnie Walker and now even BOSS (32 years with them!!!!). He may wait for a Merc slot to be empty, but that might be too late.
I don't see him going to Red Bull: if all the Fernando media factory has sustained that Red Bull decide WHO wins, it's quite strange that he'll risk going there to be beaten by Ricciardo... or maybe that'll be a perfect way to keep going with a career full of epic, drama and intrigue
OK boys, congratulations if you read all this!!!!