There is also a real herd effect. Many people will do whatever Matt Cutts tells them because they think it will be good for their SEO. Yeah right. Some of the people who are good at SEO either went to work for huge brands or quasi-competitors of Google (like about.com) that might have some ability to bring Google to anti-trust court; most of the others switched to paid advertising once they figured out that Google won't let you win at SEO.
Certainly people who write for Spamium (aka Tedium) are the ones who try herd-following methods of getting traffic and they tend to be impressed when they get 100 hits on their blog.