I think it's easy to pick on a weak example, but much progress has been made since the original "Why Johnny Can't Encrypt".
A recent example: Textsecure / Signal has been very, very smooth for me and I doubt it'd be much more difficult for laypeople either: https://whispersystems.org/
Although, like mentioned in above comments, Signal does not hide metadata, which can be as valuable to attackers as the contents of the messages themselves.
Also, in terms of adoption, it's still hard when everyone has phones that use iMessage or SMS by default. iMessage is end-to-end encrypted, but not compatible with Signal, and Android has no equivalent baked in. Using Signal requires two extra steps for the user 1) downloading/installing Signal 2) knowing about it and caring enough to use it in the first place.
A recent example: Textsecure / Signal has been very, very smooth for me and I doubt it'd be much more difficult for laypeople either: https://whispersystems.org/