Is "Zero email" a good idea?

Breton, the CEO of the large French firm Atos with 74,000 employees is implementing a "zero email" policy.  He believes that emails waste time.  The former French finance minister has not sent any emails for 3 years since he became the CEO of Atos.  Probably CEO's of many big companies and presidents of many countries do not send emails.  Should they ban emails in their organizations or their countries?

Breton wants to replace emails with face to face meeting, or instant message systems, etc.  In other words, he wants people to be able to speak BS, and every listener has to endure it without the capability to skip, delete, or automatically move it to a spam folder. With instant message systems, he wants people to be interrupted frequently or constantly instead of allowing them to respond or delete emails at their chosen time. 

My own experience shows some people (much more than I like) speak on the phone for one or two hours to make points that can be made more clearly with an email of two or three paragraphs which can be composed in a few minutes.

It is often a fun to watch the behavior of large corporations.