Beethoven and Mozart were considered radical in their day.
There's always been a generation gap in music from the time that people figured out how to make music evolve. So it's natural for older people to hate the music of younger people.
I tend to agree that the popular music of the 1960's was great and the harder rock of the 70's and 80's really emphasized the music more than the words, and the stuff afterward was catering to the demands of the masses.
But don't just hate or assume today's music is trash. There's more music for dance nowadays. There's still plenty of artists who can tell a story in comparison to the greats of the 60's. Tastes among groups causes such division, but rap has it's place as much as punk has it's place.