I know somebody who does this unironically.

Now, I do enjoy wobbly windows as much as the other guy, but apart from that I probably wouldn't be less productive booting directly into Emacs.

I am already doing email, file management, word processing, note taking, chat and programming in it, and while working the only other applications I use is a shell.

Getting used to doing that in Emacs as well probably wouldn't be much trouble.

At least not apart from the odd cat gifv sent to me by my colleagues.

The OP's author actually uses Emacs as a windows manager: http://www.howardism.org/Technical/Emacs/new-window-manager....