You can't really get away with the idea that it's OK for you to use social media as a one-way announcements mechanism. That presupposes the existence of a class of consumers. You may be on the winning side, but only because of the people who the article says need to leave the losing side.

He says, "Once you realize that the purpose of social media is to sell advertising, it may even make sense to simply buy ads." Buy ads where? TV? Billboards? Spam?

The whole point of social media is that you can target your ads to a specific audience most likely to be interested, rather than the entire public consciousness all at once. Either you can spray ads out at everybody, annoying them and wasting your money, or you can target them. Targeted ads means violating privacy, no matter how gentle or benign you try to make it.