Thanks, but we don't want another Google knowing and keeping all our data, even websites that we visit.
This isn't like a Facebook share widget, which is usually so ubiquitous, they really can know all the sites you visit.
Why would you think I'd have to use Allo and G+?
To me the spooky part is that he only thought of two use cases in which one is guaranteed that a random person is not using Google's services (at least, not exclusively).