Yeah - I remember the last time a bunch of folks got their collective knickers in a knot about music they just didn't get...
"Rock ’n’ roll has always generated controversy, as various institutional groups have attempted to portray it as a threat to community values."
"The musical style was so powerful that the white audience was infected by it, despite the social stigma that listening to “race music” possessed."
Rock 'n' roll again - replace "race music" with rap, more specifically gangsta rap.
Rap has something to say to the kids - and dissin' something because you don't understand it doesn't say anything about whatever they're listening to - it just says you're past it.
You don't need to like rap - but having a clue about generational change is a good idea, because they are the future, and you aren't - if anything, at least it gives you an idea of their take on the world you've given them.
And that, I think, is the real reason many older people dismiss rap out of hand - it shoves the failure of the shiny ideals of the peace, love and happiness folks of the 60's and 70's in their faces; less violence, poverty and racism?
Guess again.