Only a tiny percentage of users wants to use the "click through to original" feature. Sharing is a major use case that strongly benefits publisher. In the end one has to make trade offs what to make prominent in a UI.
As a user who frequently wants to change the rendering, I don't think I would have ever thought to look under share. I associate the 'share' section with tracking code and buttons for social networks.
And yet, it's what a search engine is supposed to do: link you to someone else's site.