Copypasta'd from a post I made on another board:
The Battle of the Pelennor Fields didn't need the Dead one bit. The story as written by Tolkien was perfect - the coastal people were freed from the necessity of defending their shores by Aragorn and the Dead, who fulfilled their oath by routing the Corsairs at Pelargir. They captured the ships and sailed upriver along the breeze from Valinor, sent to push back the Darkness of Sauron. As they arrived at the quay, the joy of the forces of Mordor are energized as the reinforcing ships they looked for arrived. That turned their joy to dismay as they realize who mans those ships, concurrently turning the grimness of the Rohirrim and the men of Gondor to newly strengthened resolve, and the tide turned.
There is no need to show six hours of battle to describe the ensuing rout - jump-cuts suffice nicely. Jackson used them throughout the lengthy Battle of Helm's Deep, and there was no reason not to use it here. Instead, Jackson relied on the deux ex machina of the Dead to abruptly end what should have been an epic battle. Jackson focuses on Legolas and his Oliphaunt parkour, a childish and silly deviation that wastes way too much screen time. Use of the Dead in the battle obviates the valor of the Rohirrim and Gondorians, a central tenet to LOTR. Tolkien held the warrior mythos in high regard and infused it into his central warriors Aragorn, Eomer, Imrahil and even Theoden, who rises from dotage and dishonor to regain his manhood and die a hero. Using the Dead to sweep the foe from the field in mere minutes diminishes the struggle and triumph of these warriors. Theoden's sacrifice in particular is rendered moot - had he just waited, "skulking in the hills," the deliverance of Gondor would have been affected anyway. Jackson either doesn't grasp the warrior mythos or chooses to ignore it in favor of cheap theatrical tricks, and that is unacceptable
Further, throughout the LOTR Tolkien minimizes the use of magic. This is not an accident, since he wasn't writing a wizard's story, but the story of commoners doing uncommon things. Gandalf, especially after the Balrog and his rebirth, is the second most powerful creature on Middle-Earth. In another version of the story a Gandalf-like character could have, perhaps, stormed the very tower of Barad-Dur and alone challenged Sauron. But Tolkien's Gandaf doesn't do this. Instead he acts as a catalyst, working from behind to motivate the resistance. It was never Tolkien's intent to have Gandalf conjure his way out of trouble, the story is about strength of heart and character and loyalty and love. Jackson didn't - or couldn't - portray this, so he trundles out the easy fix, and the Dead do all the work.
But Jackson's laziness goes beyond all of this. Jackson actually had the forces of Mordor inside the city walls. Wholly unnecessary, and frankly it was the cheap way out. Jackson wanted to portray the sense of hopelessness and despair the Gondorians faced in the siege, so he had the gates fall and the foe enter. This is entirely not in keeping with the tenor of the book, and further diminishes the character and valor of the Gondorians. Minas Tirith, the citadel of Gondor, had never before been breached - no foe had passed its walls. Yet Jackson throws this away just so he can show the panic and terror of his version of Gondorians.
Jackson's Gondorians are a rude, mean people. There was zero subtlety in Jackson's Denethor, from his ragged robes to the disgusting way he ate. Jackson's intent was to demean the character, again an unnecessary change. Tolkien's Denethor was a lordly man, wise and powerful, a veritable king - but in the dignity of Gondor, still merely a Steward. Denethor was honorable and strong, but his respect of strength was his flaw, and his undoing. It is not impossible to create a film character so wise yet so mistaken, it just takes work. Work Jackson was unwilling to put in.
The walls of Minas Tirith represent not only a physical but a psychological barrier as well. They are the limit to which evil can progress. They are the boundary where the reader can see that, though evil is strong and its forces clamor, the brave can withstand them. There is a place, no matter how beleaguered, where resistance is capable of halting them. The walls of Minas Tirith are no different than the loyalty of Sam Gamgee or the courage of Faramir. Jackson's decision to put the forces of Mordor inside those walls means he entirely misunderstood these themes - or that he didn't care, and intentionally trampled them for the sake of putting his stamp on the story.
Similarly, the Frodo/Shelob scene was entirely mishandled. As in the Siege of Gondor, the forces of Good are beset by an Evil entirely too strong for them. Evil can't not triumph, it is so strong. But - BUT! - through courage and valor and self-sacrifice, Evil - Shelob - was thwarted. Not, this time, by some great warrior or mighty wizard, but by a common man, a gardener, unvaliant, terrified, but bound to do what he does merely out of love for his comrade. This theme is born from Tolkien's brief time in the trenches of the Somme in WWI, where he discovered a respect for the common Englishman that as an educated man pf England's upper caste he had never before held. Sam Gamgee is an amalgamation of those desperate, anonymous heroes who fought and died in WWI no less valiantly than the "upper crust" of England's gentry.
The story, as written by Tolkien, allows the reader time to grasp the fact that the greatest hero in LOTR isn't Aragorn, it isn't Gimli or Legolas or Gandalf or even Frodo - it's Sam, the uneducated, untrained, "unworthy"bumpkin who simply refuses to give up, whose loyalty remains steadfast throughout all trials, and without whom the Quest of the Ring would never, ever have been accomplished. We come to understand this not simply because Sam bravely (and stupidly) challenges a creature more terrible than any he's ever seen or dreamt of in his worst nightmares, but through the tireless self-sacrifice and dogged perseverance Sam displays throughout the trek across Mordor.
It is that time to develop the character of Sam that Jackson tosses aside in his decision to cram Shelob and the entire stage across Mordor into RotK. Instead we're given more adventure in the form of Shelob, and adventure for the sake of adventure is exactly what Tolkien did NOT write. Jackson succumbed to the pressures of Hollywood and turned what should have been a time of enlightenment into a "rollicking good time."
