Looking at the links you posted - vim is updated once every 3-4 years, emacs - once a year. Looking at sublime text release log (http://www.sublimetext.com/blog/) it's been updated much more often than emacs and vim combined.
Honestly though. Emacs was first released almost half a century ago. Its core is fairly feature-complete. It doesn't need intense development and constant releases.
Besides, at least for Emacs, one of the main driving principles is for it to have a good & stable core, and have all the bells and whistles delivered via extensions and packages. And those extensions gets updated continuously. Often from git commit to git commit, depending on author.
When you have decades worth of customizations and ecosystem-code to consider, keeping the core stable is the only strategy you can possibly choose.
Your comparison isn't apples to oranges, it's 40 years old whisky to diet coke.
Edit: Half a century, not decade. Thanks dragonwriter.
Closer to half a century, which I guess reinforces your point.