As I've probably mentioned, good movies and bad movies - for me - have one similar point: I dwell on them. The key difference is with a good movie, I find more reasons to like it. With a bad movie? I find more reasons to dislike it. Guess which one Avatar falls in? So on this sunny Memorial Day, I will pour out my thoughts.
Warning: lots of spoilers.
The major plot hole - the one that you could drive a flying fortress through - is the fact that Jake nor Grace actually talked mining rights with the Na'vi. The whole point of the elaborate disguises was to talk to the Na'vi about mining . . . too bad they never got that far. Maybe the Na'vi would have been happy with, say, not strip mining the place, sure a little more expensive but you might be able to stop their guerrilla warfare if you did that. But, hey, I guess Jake was too busy gettin' some blue catgirl action to bother with the mission. So, right there is the giant, gaping plot hole, the first narratively unforgivable one.
The second almost equally gaping unforgivable plot hole is the ending where the Na'vi, or perhaps the planet, win this tiny skirmish like they've won some great war. What would be to stop the mining corporations to just send weapons inescapably capable of winning the war? By which I mean, y'know, satellite based nuclear weapons or terawatt lasers. We can already destroy our planet. We'd probably be much swifter to destroy their planet to get what we want. Part of what ruined the ending of Avatar, for me, was, ironically, another Cameron movie - Aliens. It's the movie that gave us, after all, "Nuke the whole site from orbit. It's the only way to be sure." Indeed. We can destroy our planet and Pandora doesn't even have nuclear bombs.
From there, it goes into many different species of mundane stupid. Like . . . how to destroy the ancestor tree their bomb was pushing some mining explosives out the back of a plane. Uh, guys, you have missiles on the aircraft you're flying. But the plan is to drop an unguided jury rigged bomb out the back of a troop transport. And why was everything so slow? Where were the supersonic fighter-bombers? I'm not even talking about the sort of support that the military will have 150 years in the future - certain to include satellite based weapons - but just the sort of things that we'd have, nowadays, to support so robust a military venture.
Also, the movie had the CGI physics problems in a real big way. It's real easy for machine to be more powerful than any animal that lives. So at the end when the charging hammerhead-aphants charged the mecha - who limbs are capable of easily supporting the mecha's own weight - almost certainly what would have happened is . . . minor damage to the mecha, major damage to the hammerhead-aphants. I mean, you try driving your head into a hundred pounds of iron - or any part of your body! Or any part of anyone's body, including any animal. And modern armor, not even armor 150 years from now, but just modern armor is much tougher than iron. Much like an elephant charging an armored car isn't really going to damage the car, the mecha would have easily withstood the stampede.
And the guns they were firing? Say they're in the 30mm range - that's about right for their size and what I imagine the function of the mecha to be in the setting - then a single shot would have blasted even the big animals apart, as they would be used primarily in anti-vehicle roles back on earth. This would be true even if the guns were "only" in the .50 caliber range. Killing even large animals is easy to do with anti-vehicular weapons. Again, that's just assuming the weapons were only as dangerous as our weapons - and the odds would be they would be much more lethal.
And why was all the glass sugar glass? Modern assault helicopter canopies are bullet resistant but these canopies burst constantly. And if their glass is so fragile, why did the mecha have so much of it? Why not an armored canopy with dozens of armored, incongruous cameras all over? Or at least less breakable glass? Like in, say, modern tanks! Even a big arrow is unlikely to do more than glance off this super-tough glass - without even taking into account 150 years of technological progress - tho', realistically, the amount of glass would have been minimized (or eliminated) in an armored vehicle at any rate.
And the big mecha vs. avatar fight at the end! The five hundred pound Na'vi parrying the ten ton mecha's blows (and ten tons is a conservative estimate)! This is the CGI physics problem, again. Indeed, that whole fight was real painful for me to watch because of the obvious comparisons to the climax of Aliens - where a slower and almost certainly weaker device would hit a much larger foe and toss it around the room. The alien queen couldn't damage the loader but some alien cat-thing can tear apart a military mecha? What happened to Cameron's sense of physics between Aliens and Avatar? The whole fight was embarrassing in large measure because of the standards Cameron, himself, had set. Again.
I also have a surprisingly complex feeling about the art direction. It was nice but I kept waiting for the Master Chief to come by fighting some Covenant. Like a rainforest but it glows! The cinematography was all about those sweeping shots meant to show you as much of the pixelated terrain as possible, but none of the shots were interesting in the way, say, The Mission was interesting (The Mission was shot in Paraguay, which is as close as you're going to find to Pandora on this earth, might I add). So, while the art direction was attractive, the cinematography was quite boring and I found the world to be a trifle too neon to be believable - and know that much of that neon would have been unnecessary if the cinematography matched the skill with which the terrain was rendered.
Which isn't to say that I hated the movie . . . the movie was too mediocre to rate that intense an emotion. If anything, this post is a reaction to the media hype surrounding the movie.