Elisp (or even better, Guile) are definitely huge reasons to use emacs for me, but there are many, many other things I use it for instead of vim (which I also know, and have used for over 20 years).

org-mode and w3m (a web browser that can be integrated in to emacs) are my two biggest draws, but eventually I mean to get the mail client working, give the shell modes another try, and maybe get the irc and RSS clients going too. The sky's the limit with emacs, while vim does more closely stick to being just an editor.

All that said, I still use vim when I need it, such as for getting syntax highlighting of strace files, which last time I checked, emacs did not have a mode for. vim is also often much faster on large files.