It does not necessarily have to be like that. The nice thing about having a templating system done right means that you can have a mixture of templates.
As far as the editor stuff goes... the easy thing to do there is honor the $EDITOR variable, or the XDG .desktop specifications for mime types, like every other decent program does.
As long as the developers concentrate on maintaining core templates and making sure those always work and not to do anything really wild and break backwards compatibility to much, AND keep the templating system as simple as possible and well documented then the rest of everybody can fend for themselves for their little nit picks like favorite editor or preferred DCS. You'll end up with something that is easily extensible like Firefox, Emacs, or Vim.
It does not have to be everything to everybody. Remember the point is to get something up and running quickly. That is 90% of the work.. after that then it's just a matter of customizing the last 10%. and only really experienced people are going to give a damn. :)