OK, now. It took me a while to sum this up and write it and + it's the truth so fucking read this!!
It hasn't died, but changed a lot. Here's, what I think, the two most important reasons to this are.
Firstly, someone mentioned old school freestylers;
A lot of oldschool freestylers "dissapeared" because a typical freestyler is someone who's in his teens.
Teenagers normaly have hobies that become significant in their lifes and occupy a lot of their spare time. But when you reach a certain age your interests change (sometimes more dramaticly).
Legend, Kantcho, Berno, Mitchy, Jay, Lemmens, Jan, Lindroth, Tobbe, Bane, Ed Yoon and myself to name a few have vanished because we practiced and made videos when we were 15,16, 19 or whatever age. Now years later some have college, work or whatever and you A; grow up and develop other interests and B; have less time and desire to train.
It doesn't just happen in freestyle. You have tons of skateborders, swimmers, fotball, basketball players etc that look promising but after they reach a certain age seem to drop out or don't give as much attention to the sport. Some more than others.
It's not the same with everyone, of course, but it's common.
The other issue is what this site is expiriancing first hand for a while now, and that is lack of active community, so to call it.
A few years back a vast majority of freestylers were active on BF. Posting videos, comments, participating in a shit loads of topics. Because it was pretty much the only place to do so.
And the beginning of the end for this was, as I noticed, when freestylers started using MSN.
Before it was the entire community (at least 80%) using the same place to chat, post videos, tutorials, challenges etc, but when MSN came along you would no longer need to use BF to show someone your video or tell someone what you thought of their video. Now there was an alternative and the more people started using it the more people started using it, if you know what I mean.
Than with MSN along came YouTube and Facebook which brought even more alternatives.
So what that did was kinda "isolating" freestylers and you would no longer have peoples ideas or comments all in the same place, but you would had to go to each person privately and get his thoughts. So you get the feeling that the community is dead, but it's not really, you just don't see "all of the posts".