votrechien - 6:31 pm on Apr 29, 2011 (gmt 0)
It's the same reason why more times than not Wikipedia is the first page shown when Googling topic- because more times than not, I want the Wikipedia page for that topic.
The big boys being shown for the big searches isn't anything new to fundamental business practices. Nearly every business book written in the past 100 years (well before the internet) will teach you that if you're a small company and you want to succeed, you must exploit a niche. And the same is true for search- it's still easy to rank well for niche search terms.