It's popular in the sense that there's still a large community which actively uses it, develops packages for it, writes about it, etc. I didn't mean to imply that it's popular in the sense that it has widespread or mass adoption.

I think the point you're missing is that Emacs just isn't meant to appeal to people who want a mouse/visual based UI. More traditional editors are "better" for those types of people, but that doesn't make them "better" in any kind of absolute sense like you are implying. There are plenty of people for whom a traditional editor is far worse than Emacs. "Better" is subjective.