I understand your sentiment. When it comes to coding, I pay attention to productivity because coding involves so many various tasks and cognitive switches that cause friction and block progress.
But writing, for me, is different. My primary progress blocker for writing is not writing. And spending time tweaking technology is so tempting, and so fun, and very much not writing.
I am, in fact, doing right now not writing, so I should get back to it. (Plain MacVim, using Latex as the markup.)
Just out of curiosity, what kind of writing are you doing? I always wonder if the combination vim+latex is something used outside the scientific area.
That's basically your age-old argument, which is fine. However, there's nothing wrong with other people optimizing their productivity even further. Personally, I appreciate people who try to tune their editing. It should be a more precise task with less effort. I don't use vim much these days but people are doing a great job in promoting precision:
http://vimgolf.com
Vim - precision editing at the speed of thought https://vimeo.com/53144573