I don't know what OP's business model looked like exactly. However, classical music is often composed and performed as full works, such as symphonies, operas, and concertos, rather than individual songs or tracks. These works are often intended to be listened to in their entirety and are structured in a way that builds upon and develops themes throughout the piece.

Another problem is that the way classical music is divided into tracks is sometimes not universal. For example, there are some recordings of Mahler's Symphony No. 5 that are divided into five separate tracks (one for each movement) while others divide it into just two tracks (one for the first three movements and another for the final two movements).

While there are many modern music albums that were intended to be listened to as full albums (e.g. "The Wall", "American Idiot" or "To Pimp a Butterfly"), I guess the track-based listening experience just won over in that part of the music world. That said, people often also just listen to a single sonata, aria, etc. in classical music too, of course, instead of always going for the 2 hour experience.