Why was the early sixties musical “British Invasion” so successful and warmly embraced in

Why was the early sixties musical “British Invasion” so successful and warmly embraced in the United States? What makes the music of the Beatles so widely popular even today?

The Doors: Do you love them or hate them?  Explain why? Was Jim Morrison ahead of his time or was he just a charlatan who mastered the art of shock value?