"Vim's biggest rival, GNU Emacs,"
No. Vim's real rival is the original vi. Many years ago I took my first look at vim. I often used vi to quickly doctor files from the MS world for use in Unix systems by removing the trailing CRs from line ends. One day I found myself using vim & discovered it had been configured to hide the CRs. If it could be configured to do that maybe it could be configured to hide other stuff? I felt it wasn't trustworthy. Since then I've avoided vim if vi (or nvi) is available.
In the light of the what the article says it's worth recalling a flame comment I once read in favour of vim based on how rarely vi was updated.