Oink and Demonoid were both private trackers started by warez kids and run like it, you got an invite because you knew someone and you kept it by keeping your ratio up. The 11-year-old on a dialup connection wasn't keeping his ratio up even if he somehow got an invite. Torrents displaced soulseek and limewire when distributed tracking meant you didn't have to have friends and not be a leech.
I was trading MP3s in 1996 on mailing lists and newsgroups. I switched straight to Oink in 2003. Napster was what the guy in the checkout at Circuit City recommended and Kazaa was where my buddy downloaded a virus that shitcanned his computer. And I'm not weird. Yeah - Napster/Limewire were definitely where the people who didn't know anybody spent their time. But Oink was the one taken down by the IFPI. It made the front page of USA Today. And regardless of how important or unimportant you feel the torrenting community to be, go ahead and ctrl-f "torrent" on that article.