I'm going to be negative once about fire and ash and then I'm going to turn off my brain and enjoy having a 3rd movie even if I'm not jazzed with the plot.
The writing was way way way too hard on Neytiri. I like the idea of exploring her struggling with feeling like the part of her children that fucks up, that doesn't fit in, that part is human. For her to struggle with that is something that I think many people who marry into the oppressors group will struggle with if they don't buy the propaganda that the oppressors are better. It's something very human, for lack of a better term,and it deglamorizes Neytiri from being this perfect, flawless indigenous woman who only is there to be eye candy and attract Jake. I like this part.
But Jesus christ the writers, and Zoe Saldaña herself, punish Neytiri for it rather than understanding that she's watching her people be destroyed. They push her conflict into "racism" against Spider when I can't understand how a mother can watch a child grow up with hers and act that way towards him. If she acts that way towards Spider, then she should act similarly towards Kiri, and Jake. When she held Jake's human body at the end of A1 and accepted him that way, she should have left much of the resentment behind that labels Spider as so OTHER, when she fights alongside Norm and let's Max and the other scientists live nearby? Wouldn't she hate all of them too, even though they fought alongside them? Confusing writing.
I was trying to give Spider a chance to shine but he's a character I simply do not enjoy. I might have liked him more, had they delved into the fact that his mother is Hispanic (Paz Soccorro) and the complexities of that identity, that human identity, on top of his love of Pandora, but he just falls flat for me. Jack Champion needed better guidance on acting or different scenes needed to be chosen, because the kid is funny and good in funny scenes, but he doesn't convey distress, conflict, pain or sadness very well as an actor. Sam Worthington carries the entire Abraham and Isaac scene on his back because I would never have known that Spider was in any danger from the way he was actually acting. Especially since I was also watching stranger things before watching this movie in the theater, and I just watched some little kids act their butts off, I was thrown back by his inability to push emotion into his face.
Speaking of little kids acting like rent was due: what is the point of Tuk's character if they refuse to use her? She gets pushed aside and used as a damsel in distress for anything ever, when we've seen in movies that children can very easily be written as protagonists or even just part of the plot. Frustrating!
I don't enjoy the Deus Ex Machina trope. Like there's a few rare instances I do and this movie was not one of them. Yikes.
Some people are defending the repetitive nature of this plot to A2's plot, but the defense of "well A2 was showing us how hard it is to defeat even one of these ships, and then A3 brings an entire fleet in to prove how they're escalating" doesn't really work very well. We're retreading the same ground again, the problem is the Tulkun are in danger this time. That part of A2 and A3 could have been compressed together but I guess losing Neteyam, they needed to break up the narrative a bit? I assume that's what happened. I still don't like retreading the same story again. Compress A2 and A3 and move the Ash tribe to be their own plot. Elaborate on the wind traders saying "transporting you comes very close to choosing a side" LIKE SORRY WHAT DOES THAT MEAN? that would have been MUCH more interesting to learn about. A3 should have been locked and localized with the Wind Traders and the kids being lost in the war, and the climax should have been Kiri adapting the customs she's learned from the Omatikaya, the Metkayina and the Tìlalim, and weaponizing her own kuru as Varang does, but not by supernatural means, by adapting her mother Neytiri's strength and warrior nature.
And what was the line about the Warrior Mother about? I'm so curious if Kiri is actually meant to be Eywa's Warrior embodiment, but seeing how the writing is relying on well used tropes (much like the first movie) and not trying to defy tropes or writing conventions, I highly doubt it.
I also can't personally stand dead characters getting revived even with an in-universe explanation, and the idea of recoms opens up a can of worms bigger than the story cares to tackle - a recom could be someone's way of living forever, similar to altered carbon, because what is stopping humanity from simply making human recoms? Literally nothing! If they can make recoms, then the lower class is also endangered by merely being in the way of resources for the rich and powerful who want to live forever.