It's not about the First Amendment. Hiding each economic decision behind free speech is phony. While it's easy to rate the popularity of a site, its quality and relevance are often harder to measure. Among other things, it looks at how often the site is bookmarked, how many votes it receives, how much time people spend on the site, and how often they come back. And that kind of numerical criteria can make for some bizarre ratings.
Technology companies tend to look for a technical solution.
But this needs a human one. But the company says Cooper wanted it to remove offensive sites from its database, which it considers outright censorship. Civil rights groups were upset when the company categorized Holocaust-denial books as World War II history. Amazon responded by creating a separate sub-category for such literature. Anti-hate groups in the United States rarely call for the removal of an offensive site unless the company itself has strict policies against racist material.