I disagree. I'm not sure Google+ is uniquely suited for anything, but I am sure I could make an equally convincing argument for mailing lists or fuller-featured discussion boards as better platforms for discussion. The article is simplistic.
Google+ trumped up the circles feature as a way to manage privacy settings. My (admittedly critical) reading of your post makes me think that's the only feature here worth discussing, and I don't think it alone is responsible for greatly improved conversations, especially when compared to the many other options for online discussion, and certainly not among computer scientists specifically.
A better explanation is Google's already pervasive presence (especially among computer scientists), and their monopolistic method of forcing Google+ on, for instance, GMail users. I'm not sure there are any technical decisions they made to support your thesis that their platform is uniquely suited for anything really.