OK, lots to unpack here.
Firstly, I am pleased you enjoyed Avatar and that you are looking forward to the sequel. I suggest you cease giving an airborne fornication about the statements of the kind you list at the start of your article, and just like what you like. It would be boring if we all thought the same way and enjoyed the same things. :)
I do not care for Avatar. I saw the film in 2009 during the original run. I thought it was technically brilliant, as one expects from James Cameron, but for the first time ever, I didn't feel satisified by one of his films. To me, it was simply Dances with Wolves meets The Matrix on another planet, with none of the emotional heft of the former or excitement of the latter. By the way, I love Dances with Wolves (no, I haven't any time for eye-rolling white saviour narrative blithering, as that film was clearly intended as a corrective to Hollywood's treatment of Native Americans, not to history, and it's heart is clearly in the right place), which is another reason I probably felt slightly narked by the blatant plot steal.
I probably could have been a lot more forgiving, if Avatar had a sense of humour, but it really did feel like Cameron was bludgeoning the audiences with his overly simplistic, student politic pro-environmental/anti-capitalist messages, to the point that I inexplicably got the urge to strip mine a third world country and oppress its population, just to spite Cameron. Not the reaction he was hoping for, I'm sure. But I've never been in favour of inserting deliberate, po-faced preachiness in any film, book, play, TV series, or otherwise. I believe by simply telling a good story first and foremost, what is important to the writer becomes inherent in the text in any case, without the preachiness, and consequently becomes far more potent. See Tolkien's The Lord of the Rings, as an example - and I wrote about that subject in general at greater length here, if you're interested: https://medium.com/illumination/be-a-storyteller-not-a-preacher-991a6efecb6f
I will approach the Avatar sequel with an open mind, knowing I once felt thrilled to see a new James Cameron film (I was 14 when The Abyss came out, and I was one of the two people who actually saw it in the cinema during the original run, since that is the only Cameron film not to terminate box office records). But I do think the rule of thumb with Cameron, in general terms, is the bigger his budgets, the less interesting his films get. I still think The Terminator is his best film, and then Aliens.
Speaking of The Terminator, to address the various other film series you invoke:
1) I also ignore the Terminator sequels. Beyond the first two, there is no good artistic reason for the others to exist.
2) I feel the same way about Alien. There is Alien. There is Aliens. The rest are bastard children.
3) Avatar isn't The Godfather, and nor should it be.
4) I also loathe Twilight (or Twiglet, as I call it) and Fifty Shades is simply abysmal. If you want a good BDSM film, try Belle de Jour, Secretary, or The Duke of Burgundy. And here are some suggestions for good vampire films that arent' Twiglet:
https://medium.com/fan-fare/my-ten-favourite-vampire-films-67aab68109d6
5) The Matrix is a pretty good film. The sequels are all rubbish and entirely superfluous to requirements.
6) The Marvel films are generally solid, as you say, with a few outstanding films (for example, Captain America: Civil War, my personal favourite).
7) Jurassic Park/World: The original is a classic. The Lost World is actually a much better sequel than anyone gives it credit for, though it fails to match the original. The rest are fairly unremarkable.
8) Transformers: I loathe Michael Bay films with a passion, and Transformers represents a particularly braindead nadir. But I quite liked Bumblebee.
9) Planet of the Apes - The original is a classic. The initial four sequels are wildly inconsistent, and the less said about the Tim Burton remake the better. But I do like the more recent trilogy.
10) Star Wars - The original trilogy are a sacred text of my childhood and no longer merely films, but a rite of passage for children. The prequels fell flat (despite being technically proficient) but I actually quite liked The Force Awakens, although I do agree it is nothing special. The Last Jedi however, I think is rather good, and I'm a staunch defender. The less said about The Rise of Skywalker the better.
To conclude, here's why I feel much the same way about The Last Jedi as you do about Avatar: https://medium.com/cinemania/the-real-reason-some-star-wars-fans-hated-the-last-jedi-f4c142b85cfc