I learned emacs before vi, but I could never remember all of emacs' complicated keystrokes. It feels as though there are far fewer commands to memorize in vi, and the commands that I do memorize are also useful for writing sed scripts--so the payoff of a little memorization in vi is greater than the payoff in emacs.
And anyway, I'm a minimalist (that's why I run OpenBSD). nvi is fine--vim and emacs just have too much bloat.