I agree, I found that aspect of the article confusing as well. It's very clear why it isn't part of iMessage. Though you could make the argument that by allowi

I agree, I found that aspect of the article confusing as well. It's very clear why it isn't part of iMessage. Though you could make the argument that by allowing manual key verification, Apple increases its trust with technical and privacy-conscious users. And while the vast majority of people might never know the feature exists, the technical users would become strong evangelists for the company's products. It's a good long-term strategy for Apple to try to get the privacy and technically minded users on their side.