Cinema is a bigger industry because it's more commercialized. You can make music in your basement or in the middle of Zimbabwe, it's more of a natural thing.
The average human consumes music more and will always use it more even if the music industry is below the movie industry. Not to mention music has existed long before movies. Music is naturally everywhere, YouTube for free, radio for free, etc.
And honestly you could argue people respect music more. People are willing to pay $300 for a two hour concert.
Who's willing to pay $300 for a two hour movie?