Why is classical music unpopular? I believe because it’s so easy to hear it without actually paying attention to it. Since it has no lyrics (aside from opera - that’s a whole other story), it is easy to not relate to it and to even see it as some sort of background music. To really appreciate it, you must really listen to it.
Classical music is written purposefully. Each note is written for a reason and must be played with a purpose. A true classical musician understands that every single note must be played intentionally, and this is why it takes so much skill and years of playing and studying to be able to understand how to convey a message through classical music and how to reach people emotionally through it.
As listeners, when we hear a piece, we hear the final product, and we easily ignore the details - or not even notice them. If we truly listen, we can hear all the minute details that were applied on every single note - the little crescendos, accents, changes in tempo, or a pause just long enough and short enough to re-captivate your curiosity.
That is the difference between hearing a piece versus connecting with it and feeling it in your heart. It is also the difference between someone who plays a piece just to show they can play it - versus someone who is able to enter your soul through music.