So the whole push for SSL/https from Google has been opportunistic rather than good practice. I mean why would a search engine go as far as to make SSL a ranking signal?
Sites that use or at least offer SSL probably also tend to be higher-quality sites. The combination of verified identity and payment means that it's a natural filter for people who are at least semi-serious about their project.
> I mean why would a search engine go as far as to make SSL a ranking signal?
Because any number of 3rd parties have been injecting their ads and other crap as MITMs. SSL is a better, but not foolproof way to make sure the content you get was the content served by the remote server.