Many people really like music, but very few feel inspired to make music, i.e., compose. This seems unique among art and hobbies. Why?
Maybe they don't actually like the music but more the community of people who also enjoy the same genre of music. A game theoretic coordination game. But this argument could be applied to any other art.
Maybe composing sets the bar too high. Many people play covers on musical instruments (including karaoke), DJ, assemble playlists and curate libraries of recordings. All these are derivative works contributing to music as an art form.