A key point of modernism is that it was self-consciously "artistic" in the sense that it deliberately sought to find new literary forms, built on and alluding to existing works in the canon. Modernist authors didn't only write to entertain but set out to create works that were likely to feature on the emerging literary syllabuses of the early 20th century. Take Joyce's famous alleged quote about Ulysses that:
I've put in so many enigmas and puzzles that it will keep the professors busy for centuries arguing over what I meant, and that is the only way of insuring one's immortality.
In many respects beat literature, with its focus on spontaneity and the lived experience, is the opposite. It's been accused of being anti-intellectual and in fact, there's already a question on the site about this: The Beat-Generation and anti-intellectualism
I'm aware that some authors in the modernist tradition supported emerging beat authors - William Carlos Williams corresponded with and encouraged Allen Ginsberg for example. But nevertheless, the contrast between the two is so strong it made me wonder whether a purposeful rejection of modernism - or at least its more austere aspects - was part of the point of beat literature? Did the early group emerging at Columbia University deliberately try to move away from the modernist style?