Changing their policies now hurts non-profit organizations like the Blender Foundation and is in effect a bait and switch. Google is using at this point its monopoly to coerce their partners and users into accepting whatever the heck they want. Personally I don't understand them. This is clearly about a very popular channel that is bringing them eyeballs.
I also have no sympathy for their need to monetize — several years back we had a protest in my country against a gold mining company and the YouTube videos made by protesters where preceded by ads of the mining company, ads which were lying and that couldn't be reported for that.
Ads on YouTube are dangerous as they aren't just about products or services, but about social and political issues too and whomever has the bucks to pay wins more attention. As an author, having the ability to disable ads for certain videos is common sense.
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Also, Google, I would have registered for YouTube Red to pay cash for an ad free experience, but you haven't made it available in my country yet and I've been waiting for a long time.