Roel Weerheijm, studied at Dutch Literature answers ...
Chopin is very likely the only important 19th century composer whose musical oeuvre largely ignores Beethovens influence and innovations. It can't be underestimated how daring it was of him to clearly follow his own musical path.
Nonetheless, Chopin played Beethoven's music, admired Beethoven for what he had accomplished in his pianistic works, and assigned his pupils to play Beethoven as well. He preferred Beethoven's Ninth Symphony over Berlioz’s Symphonie Fantastique. But he never seems to have been really passioned about Beethoven's music, let alone incorporate his style, borrow or imitate his stylistic templates like almost everyone else did.
His teacher Zwyny apparently ‘had no time for Beethoven'. In respect to contemporary music, he only approved of the music of Hummel and Moscheles; his older heroes were Bach, Haydn and Mozart. Chopin learned his music, as a pianist and as a composer, through Zwyny's own preferences. Chopin added to them his admiration for Ries and Kalkbrenner.
What these composers have in common, is a love for a slender, rather lean, clear sound. Ries, Hummel and Kalkbrenner used rather conventional structures to express subtle, virtuosic and melodical ideas. Haydn and Mozart were great Classical composers, inventing and improving music that focuses on rationality and structure. They also wrote rather lean and clear, at least when you compare them with what came after them: the impressive, lengthy, layered, dramatic, philosophical structures that Beethoven (and Schubert) wrote.
Beethoven expressed a far more complex and holistic view. In more than one way, it makes perfect sense as a logical progression from the traditional Classical approach to music. But this clearly wasn't what Chopin wanted in his music. He rather focused on another important progression from Classicism: that of the lighter, structurally convenient, lyrical post-Classicistic music.
(On a side note: nowadays, as we’re still extremely impressed (and righteously so) by the big innovations of Beethoven and Schubert, we largely forget the early 19th-century stream of (post-)Classicistic composers, with a.o. Field, Spohr, Hummel, Paganini, Kalkbrenner, Von Weber, Moscheles Cherubini and Ries. In Chopins time and milieu, however, these composers were as important, and likely more popular, than Beethoven and Schubert.)
Again, it's not true that Chopin ignored Beethoven. At a certain point in his career, for instance, he toyed with the idea of writing variations on a Beethoven theme for piano and violin, together with the befriended violinist Slavik. We don't know which theme, however, and the idea sadly never materialised, due to Slaviks early death. But Chopin had his reservations: Beethoven, he said, can be obscure or even incoherent because he turns his back on eternal principles and because he can sometimes be too passionate. Also, Chopin found Beethoven at times vulgar.
The musical revolution of Beethovens works and his views on what it meant to be a composer not only made him popular and loved by some, but he was also misunderstood and disliked by others - a.o. by Chopin. He thought of himself the way virtually all composers before the dawn of Romanticism thought of themselves: as the noble, humble craftsman, and not the typical bohemian artist that came about in the early 19th century.