While I agree the depiction of
Sauron in Jackson's films are not true to
Tolkien's works, but I think they did a good job at what they meant to achieve. Peter Jackson was trying to make a film that would capture the core of
The Lord of The Rings in the form of an action adventure movie for everyone, so characterizing Sauron as a physical, armored soldier made the threat feel real, powerful, and fully fleshed out without the need of greater description. Mass audiences can resonate more with a physical entity of great power that looks, acts, and feel scary and dominating. I find it quite silly and a little over the top for Tolkien's world, but for a movie made for the sole purpose of being a movie, I think they made the right choice.
As for the physical eye at the top of
Barad-dur, I again find it silly and an over exaggeration of Tolkien's description, but again, for the sake of the film, a physical eye makes the threat of Sauron feel real. In the book, Sauron's influence is there in spirit and that works great for Tolkien's world, but in the movie's it feels like Sauron is there and he is here in physical form and he is gathering strength and will soon return to this other physical brute like form that was shown at the start of the film.
I do not deny that PJ's depiction of Sauron is a little absurd and somewhat goofy, but I also think that it makes the story feel more important to mass audiences who came to see these films as just that, films.
