There have been long term (10-years) problems with Google first creating webmaster guidelines and then with manual enforcement of the official Google guidelines. In my opinion Google has done some very great work with many of the algorithms they have developed and enhanced over the years. The worst and most terrible mistakes have come due to human error and inappropriate censorship by Google.
The Internet war against real spam is still a huge problem and Google needs to focus on the basics of fighting spam and the manual spam police need to do a better job of finding and fighting real spam and not harassing small business people unfairly.
E.g. I can easily create a long list of sites that still have "Sponsored Listings" that pass PageRank.
As a webmaster the following is an excellent article that you should read regarding what Google does penalize and why.
Google has illegally broken into my Blogs over 100 times. Google is editing, illegally deleting my content, and damaging my Blogs. Google wants to hide the evidence of the felony crimes that they have committed against me and my family. Sundar Pichai the Google CEO is a CRIMINAL.
