Wanting what was in the original Uncanny X-Men Dark Phoenix Saga fails to take account of the fact that
1) Fox has a hard-on for Wolverine. (Even Jackman does!)
2) Singer and his creative team (writers, production designers) left
3) The actor playing Cyclops left
In an ideal world, we'd have seen Jean returning as 'good' Phoenix, doing something majestic/heroic with her power that gave her a cosmic thrill and perhaps inadvertently caused harm/injury to a large number of people (like the scene in UXM where she stops an attacking helicopter but kills everyone in it), wanting that sensation again, being counselled (and corrupted) by empathic Emma Frost, turning to darkness to seek that sensation, doing something devastatingly terrible (feeding on a nuclear power station? causing it to blow up, equivalent of the D'Bari sun incident), and eventually being tackled by the X-Men and somehow dying... That would have been a fair adaptation of the classic saga and avoided the more way-out elements (Mastermind's time-slip illusions, outerspace travel, consuming a sun, M'Krann crystal experience etc).
However, it's not an ideal world. Fox loves Wolverine (and Magneto too, it seems) and the writers felt the classic saga's far-out elements made it hard to adapt (though I've just given you a thematic adaptation rather than a literal adaptation, that skilfully avoids the crazier stuff, so it is possible). So they used elements of Endsong and Planet X instead, saying the more modern stories were better templates for movies (which is true, in fairness).
I prefer to see these various interpretations as just that - variations and interpretations. I'm just re-reading the Ultimate X-Men stories which have Beast being killed, Sinister being a musclebound, stammering assassin, Storm being an illegal Moroccan immigrant who tries to get it on with Wolverine, and so on. Just as Smallville is another 'take' on the Superman mythos (as was Lois & Clark), just as the earlier Batman movies varied in tone and creativity from one to the next, just as the various X-Men comicbook continuities vary, so it is with the movieworld. The movies themselves vary from the source (with varying degrees of disappointment for fans) and the third movie varies stylistically and conceptually from the previous two although picking up basic strands like Jean's return, Magneto's war, Wolverine finding a place for himself, the challenges of Iceman/Rogue's relationship, and Storm's insecurities and turmoils that have led to her hiding at that school for so long.
A new creative team was always going to join the dots between those strands in a different way to the previous creative team. Those of you worshipping Singer's 'vision' must realise that he is not alone in having a 'vision', an interpretation of things, a way that he does things which is fairly specific to him. When he left, his exact vision went with him and I think it was up to people like Arad, Winter and Shuler-Donner (who've been there from the beginning) to ensure the tone was totally consistent when a new creative team came in. But don't be so foolish as to believe that a new creative team is ever going to be an undetectable clone of the previous creative team. You want the impossible if you believe this.
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