It's the same thing that drives people to want to experience sexual pleasure or have one too many drinks. We all want to experience the other, and to get out of our daily existence.
I always had this thing, when I was younger especially, I didn't want to do movies that much. I found they took a lot out of you and they were exhausting for me in a lot of ways.
The public want actresses, because they think all actresses bad. They don't want music or poetry because they know that both are good. So actors and actresses thrive and poets and composers starve.
You will never get to the irreducible definition of anything because you will never be able to explain why you want to explain, and so on. The system will gobble itself up.