Maintainer here. Thank you for the thoughtful and articulate feedback! I appreciate you sharing your perspective and I'll give you some of my thoughts.
> How's that compare to emacs? It sounds like it can be extended with Vimscript or JavaScript? Emacs has several snippet/templating options, and of course it also has several autocomplete options.
Every editor is an exercise in trade-offs. Emacs, Vim, VSCode, Sublime, Atom - what defines them is their trade-offs and execution. The strength that modern editors have is that you get a lot working out of-the-box - when I boot up Emacs on Windows (or gVim for that matter), I get a (subjectively) ugly UI with no language support. That's not to say I can't configure it to look and function beautifully - but the trend with the modern editors like Atom & VSCode is to have an 'it just works' mentality. If you have a finely-honed Emacs config, sure, there might not be appreciable benefits for you. But a new user may not want to distill the several snippet/templating options.
I'd compare it to a car - a passionate driver might buy a kit car and finely hone the transmission, handling, etc. They probably won't be happy with the automatic transmission they find in a car at the Nissan dealership... But the automatic transmission ends up being convenient enough for a lot of people.
> I really don't understand what the value proposition is here. Rather than using Electron and JavaScript and Vimscript and an ancient C core, why not use X/Cocoa/WinAPI, elisp & a relatively thin C VM?
The reason I open-sourced the project was because I wanted help developing it. That's part of the joy of open source. And when you look at technology trends, like the [StackOverflow Developer Survey](https://insights.stackoverflow.com/survey/2018#technology), if I want others to help me, it makes sense to use the most popular technology today.
> From my point of view, all of these huge environments built atop vi are simply reinventing emacs, poorly — and worse, they're destroying the wonderful things I always loved & respected about vi!
Yes, I think we have two different perspectives here, and that's okay. What I love about vi & vim is the modal editing aspect - I think the composable, modal language is a beautiful and efficient way to manipulate text. That's the piece that's important to me.
> Certainly, folks should be free to follow their bliss. I don't really begrudge the Oni guys their project (although I'd obviously love it if they spent that energy & brilliance a little further up the stack, e.g. by making a great text/GUI browser mode for emacs) — I just don't get it.
Cheers :) FYI, our 'editor' implementation is extensible, so it doesn't preclude having another sort of driver - it'd be technically feasible to plug something else in there, too (in fact, we have some pure javascript 'editors' that we use as test cases). Not inconceivable that someone could drop-in an editor that talks to Emacs, Xi, etc.
But at the end of the day, I recognize that the trade-offs we make for Oni are only going to appeal to a niche of users. Having new editors exploring different possibilities can help the whole ecosystem, even if it doesn't directly target your niche - as other editors get inspired by the 'good parts' - and at the end of the day we all end up with better tools.