What's the big deal?

I keep reading derogatory things about people who walk around listening to their i-Pods, and I frankly don't understand it. It's not like it's a brand new phenomenon - people have been walking around with Walkmans for over a decade. It's not like the number of headphones has increased tenfold, it's just that people have converted from CD/Tape/Radio to digital. So why all the attention now? Or is it really that big a change outside of the city, where subways have been filled with people rocking to their own personal sound systems since boom boxes went out of style?