I think that one big reason is relating to the artist and or song writer. If someone is 22 years old it is hard for me to relate to their experience- especially when it may be very different from my own personal experiences at that age, which is fast approaching forty years ago. Today many young artists are extremely tenanted and their work is highly professional in all ways, but their perspective is not something that I am always willing to pursue.
I do like new music but it is more limited in scope. Plus there are so many genres out there these day, who has the the time to listen to it all?