Echoing others, I've been using emacs for close to 10 years now. I've been keeping a close eye on Atom because it's the firs time I've seen a editor start to gain popular appeal that can approach the customizability and power of Emacs.
The other thing holding it back is performance. It might be something that Atom can never be "good enough" at, but I have hopes, if only with increases in compute speed.
Not really, is just that emacs is such a powerful programming environment that it's strange to see someone that knows it, leaving it, because the alternatives doesn't really offer much in return IMO.
I left Emacs for Sublime a few years ago, after almost 20 years of Emacs. Sublime isn't the greatest in feeling native to the platform, but it does better than Emacs. I prefer to spend my time on my projects instead of the editor itself.
i've been only using emacs for about three years. Don't get me wrong it's the great. I'll never truly let go of it as i use it everyday just for org-mode itself. But i always wonder how other text editors are doing, especially an up and coming one like atom.
The other thing holding it back is performance. It might be something that Atom can never be "good enough" at, but I have hopes, if only with increases in compute speed.