I don't agree.

When that paper was written, "Google" referred to an academic research project, not a company. Page and Brin indicate that because other search engines were developed at corporations, they were "largely a black art" and advertising oriented.

Since Google has become a company, and is no longer a research project in the academic realm, it has become a black art and advertising oriented, just as Page and Brin said happened to search engines developed at corporations.