Well, to be fair, the music these young people listen to probably isn't WORTH spending money on anyway, and it's usually going to be 192 (or 128) kbps and played through crappy headphones or laptop speakers, so more power to them.
If it's worth money, people will buy it. The music that gets streamed is the pop stuff that, to be honest, already makes enough money elsewhere, and those artists/record companies/etc. etc. still get their money. It's the less-popular ones that probably should, and DO, get fans' money by purchasing songs/albums.
Either way, it is a huge change in the way music is presented and listened to, and for all we know, it could lead to the downfall of illegal pirating. If music can be streamed and offered online for free, why bother with torrents and shady download sites?
-Marc.