Bernstein was almost certainly the most gifted musician in American history and a better melodist than Beethoven. Keeping in mind that writing melodies isn’t the end-all be-all of composition. Obviously Beethoven was a greater composer. Tchaikovsky also wrote better melodies than Beethoven but was not a greater composer. The ‘Ode to Joy’ melody, played on a piano without the bombast, is a very, very simple and diatonic tune. There’s nothing remarkable about it at all. Beethoven probably chose the tune because it was so simple and so reflective of *all* of humanity - high and low.
Louis Moreau Gottschalk was a better composer than Leonard Bernstein. Hell, Stephen FOSTER was a better composer than that tired old phony. In fact, it's arguable that Frank Zappa or Barry Manilow could out-write Bernstein. If not for the support from his ivory-tower effetes, Bernstein would have spent his career sweeping up Carnegie Hall.