There are valid critiques, of course, but if you consider The Hobbit and The LOTR films as a whole, he's directed what is beyond question-in my opinion, at least-the best film franchise to date.
And certainly the best adaptation of a fantasy novel I've ever seen.
To some extent, the criticism is justified when Jackson is adding new characters that didn’t exist in Tolkien’s world, like the elf-dwarf love interest.
It is also not warranted when Jackson is adding to the story from the background established by Tolkien. An example of this is the Arwen-Aragorn love story. They were lovers and they did marry and they both died. It was a valid addition, imo.
#3 The movies are pretty good but in my opinion just way too long. Plus Hobbits are funny looking when next to humans.
My only complaint is no Tom Bombadil.....