One of the
oddities of
mainstream popular music is that it's pitched to people in their
mid-teens. Eventually, people
grow up and become less interested in
music that is pitched to teenagers. At the same time, the music of one's own
teenage years retains a strong
nostalgic appeal.
This goes a long way toward explaining why so many people who are 30 or older think that today's music sucks.
It would be impossible to measure objectively, but my guess is that popular music at any give time is about as entertaining as it ever was in the good old days.