Calling it a "free and open channel" when 80% of consumers are on Microsoft/Google addresses that control who can deliver e-mail is laughable. It's dead, Jim.
- it was a way to outsource the mail server administration and already free in our corporate package
Which is pretty much all I have from the corporate side. On the personal or small business side its most often
- I don't really care that much about running my own stuff
- I needed a personal email address
All these are valid reasons/motivations but none explicitly argue that email messaging should become proprietary.