"[t]yping in // has just resulted in people overusing their index fingers, wasting time and using more paper".
The rest of the address is relatively important for the browser. Back in the "olden days" of the Internet, there were http protocols, gopher protocols and ftp protocols - and all followed with a colon and a double forward-slash. Now we have more protocols which are used, such as Skype and AIM to initiate a VoIP call or an instant message.
But there is practically no reference to the double forward-slash on the web, or as to why it is even there. In an interview with The Times of London, he could have easily redesigned URLs not to have the double forward-slashes in. Perhaps as a result, it would have reduced initial frustration, confusion over web addresses and saved on paper.