There is the rub. These movies are evidence that Tolkien succeeded in his ultimate goal. Creating a mythic past for England. The Lord of the Rings is a myth and as such there is no "right" or "wrong" way of telling it.
Imagine it this way. Tolkien "found" original sources and novelized the myths he "discovered". Jackson then read the same sources Tolkien "discovered" and made a film version.
The novelization isn't the "true story", it's just a particular way of telling the story. Jackson's films aren't the "true story" either, just his way of presenting it.
Tolkien has won. His "myths" have taken on a life of their own.
That's the point I've been trying to make over at the HH and other threads. Thanks for making it much better than I have been doing.