It's two clicks, you need to be really explicit about it. The first click opens a huge "You're about to turn on sync" dialog, where you have to click "Yes, I'm in" again.
I don't disagree with the general sentiment, but the article isn't factually correct. It's also by the same person who misunderstood the recent chrome changes and wrote a long blog post triggered by them misunderstanding what was going on (https://motherboard.vice.com/en_us/article/gyny83/google-chr...).