Ever since I switched to emacs, I’ve read more source code than I’ve ever done before. I’ve even found and reported several bugs (in org mode and a few other plugins) with detailed and precise bug reports.
In some other program (say, LibreOffice), I would have passed off any bug I encountered as just another quirk in the system. But, in emacs, due to the ease with which source code can be read and modified from within the running instance of emacs itself, I have felt very encouraged to read up and understand what’s happening.
Free software is good, but emacs goes one step ahead and encourages people to actually exercise their freedom, study the source and contribute. People become more than just “end”-users and consumers. They become creators and contributors as well.
One of the original ideas of making emacs a programmable editor was to encourage and get even (normal) lay people to learn a little bit of programming for their needs and thus promote computer literacy. And, emacs actually has a way simpler learning curve than something like vim. You could know nothing about all the key bindings, and just use it like nano or gedit. Given all this, it surprises me that emacs has become known as an editor for geeks and has acquired such an intimidating reputation.
Please note: I’m not trying to start any editor flame wars here. I’m just posting out of curiosity to know why people don’t use emacs, and to see if I can change anybody’s mind about it. At the end of it, your choice of editor is completely up to you, of course.