Not sure why anyone doubts or is upset by this. In my field, health professionals send all sorts of critical confidential information in email, and never delete

Not sure why anyone doubts or is upset by this. In my field, health professionals send all sorts of critical confidential information in email, and never delete any of it. For each person where email has good enough security, or can be made as such, there are 10 where it will never be remotely adequate in real world usage.