> As a user, my experience with HTML/CSS/JS apps is great. Look at the excellent feedback the Atom Editor is getting.

For some less positive feedback on Atom, which reinforces some of creshal's points, see the Atom section of this text editor rundown:

http://eev.ee/blog/2015/05/31/text-editor-rundown/

I've also frequently seen complaints to the effect that Atom is much too slow, even on machines only a few years old. Even my 486 laptop back in 1997 could run a text editor with syntax highlighting (specifically, JPad for programming in Java). What are editors doing these days that needs so much CPU power?