This has been my experience. With Google I am constantly asking myself: Wait, what about all that glorious, smart, noncommercial web content that I
know exists? Like the Stanford Philosophy Encyclopedia[2] or that economics professor's dataset that I remember being referenced in a podcast a year ago?
Google seems to have decided that Wikipedia is the only blessed noncommercial source of intelligence.
I guess, if I were to put it strongly, I'd say: using Google is not like using the Internet any longer.
FWIW, HNers may wish to check out Yewno[1], a knowledge search engine based in Redwood City that I've had the pleasure of being (tangentially) involved in.
[1] http://yewno.com
[2] Yes, I know this is indexed. It just frequently gets buried in my searches.