There are a lot of ways to look at it. The "You're not the customer"-perspective: You as a user of google search is not the customer. The customer is the peopl

There are a lot of ways to look at it. The "You're not the customer"-perspective: You as a user of google search is not the customer. The customer is the people placing ads on Google search, and secondary the people placing ads on the pages google search leads users to. The "its an algorithm"-perspective: Google is a search engine, not a collection of curated links. In the past, Google has been very much against having human rate results, but I think they actual have focus groups that come in a lab and do some searches and rates what they see (under the guise of being a different search engine, most likely). Google is very conservative about adjusting their algorithm (or at least have been) and small changes can lead to huge changes in income.