Business is Business
This article and IETF are correct we need better inter-communication encryption for email transport, and more.
I don't care if you don't encrypt your email from end to end, but I do care that it is encrypted when it is exchanged between client and server and/or between server and server.
I have been asking Government to provide Self contained National Secure Email service for Australia, It would be good to reduce phishing as the addresses could be monitored. To avoid leaking links to external locations it would be required that images such as logos were embedded in the document using formats such as rtf (Rich text format) or pdf (postscript document format) and an archive format Zip/7zip, Lha/Rar. for attachments, the cover letter/ cover page would be plain text and tell you of the attachments, such as a bill from your energy supplier, simple encryption could be used for obfuscation these simple methods could include zip or pdf password.
If the end-user chose to further encrypt their documents it would be up to them.
The point is that in Australia most corporations do not extensively use email for public business communication. Just try to find a Banks or Superannuation's email address for "General Business" or find the CEO's email address. They could have an electronic mail room if they so choose.
Many companies provide some email access for customer service, often these are squidgy windows without a full page space to write in, whereby you have to log into their website first before you can enter your question or complaint into the box provided. Some provide internal mail and notify you via SMS to your two factor mobile phone number that they have sent you something.
It is obvious that many of these organisations do not have confidence in these internet systems, while they push their customers into ever more convenient but risky internet access as a substitute for customer service.
While sometimes I churn my ISP causing my email address and phone number to change, I am sometimes pushed to Yahoo or Google mail products as the ISP doesn't provide email, and so I am left to rely on what ever these free email client and mail products will do.