Tolkien's style of writing, even at the time, was incredibly old fashioned and dull. He was greatly influenced by poets like William Wordsworth who specialized in pastoral poetry hundreds of years previously. Even in the 1950s, writing that drones on and on about shrubbery and forestry details was viewed as uninteresting. And the reason the LoTR films are better than the books is just that. The story was great, but it was buried in a mountain of long-windedly-bad writing.