Google was forced into that by improved "search engine optimization". SEO used to be about things like keyword stuffing, but as Google made their search engine smarter, SEO companies made their search spamming smarter. There are now SEO operations using machine learning to reverse engineer Google's algorithms and then automatically spam just enough to stay under the threshold.
In 2010, Google tried using "local" data to improve search. That turned out to be extremely easy to spam. A classic example of this can be found by searching for "laptop repair bradford pa". This brings up "Illusory Laptop Repair", located in the middle of a railroad crossing. A SEO expert created that phony business listing to demonstrate how bad Google was at detecting such spam. Google still thinks it's real.
In 2012, Google tried using "social" data to improve search. That worked even worse. Fake Google accounts created to create fake "+1"s may have exceeded the number of real ones. Google "+1" are still for sale; the going rate is about $0.10 each.
Meanwhile, links aren't as useful as they used to be. Who creates a link to a retail outlet other than on social media any more? Google is trying all sorts of "signals", but in heavily spammed areas, they're not doing all that well.
Yandex has been trying search that doesn't weight links at all for some heavily spammed categories in the Moscow area. It seems to be working for fake real estate ads.
(We have a partial solution - find the real-world business behind the web site and check it out in hard data sources, such as Dun and Bradstreet or Experian, which have business credit data. See "sitetruth.com/doc".)
This doesn't seem to work.
This is what I found: https://maps.google.com/maps?q=laptop+repair+bradford+pa&hl=...
Why use humans? People can decide if your navigation is intuitive. They can decide if your page looks like crap. If 230,000 people are searching for "coconut oil" per month (actual numbers) then it's worth having an intern spend 15 minutes to make sure page 1 of "coconut oil" looks right.
Google can afford that. They need a human to decide if the "user experience" is actually good vs. disallowing the back button and forcing the browser to crash, which is how I suppose you could fake a "time on site" metric if this was just an algorithmic problem.
Google is now more like playing Zork. You type "Go North" like 10 million other people before you typed "Go North" and Google has already crafted that experience you'll find in next room. (Which makes me wonder, do they score how boring you are based on predictability?) This is becoming more and more obvious over time as a search for "calculator" shows you an actual calculator that a human at Google created. That's not an algorithmic response.
Similarly, I see that human touch coming more into play with voice recognition, Google Glass, Siri, etc. Call that "AI" or whatever. You ask Google a question and Google has already sculpted a slick answer based on tons of testing. That's how I see Google as a search engine now. Part of the crawling is interesting (recognizing objects in photos?) but I think human reviews of all the important websites and SERPs, that's harder for a competitor to reproduce.