My bet: 1. Advertisers don't want to be featured on an ISIS recruitment video, or something like that. 2. Google implements a filter. It is fuzzy and based on

My bet: 1. Advertisers don't want to be featured on an ISIS recruitment video, or something like that. 2. Google implements a filter. It is fuzzy and based on machine learning, because Google are strong believers of machine learning. 3. The algorithm let a single ISIS recruitment video through. Advertisers form a coalition and yell "NO ISIS RECRUITMENT VIDEOS!" 4. This forces Google to implement either whitelists, or tune the algorithm for detecting bad content such that it produces a lot of false positives. 5. Most people are now demonetized, and since the system is based on machine learning, it is not possible for Google to tell you exactly why the neural network decided what it did. It is clear that the current demonitization algorithm hits unfairly hard on content creators. It forces them to run a Patreon-model. I'm willing to bet that Youtube is now powerful enough that people are willing to pay for content and no ads for certain channels, so in the end this is not necessarily good for advertisers.