[philix001]

People are free to fork open source projects. tarruda tried to merge the async job system before forking vim. Bram has the right to deny the patches, but the most successful projects are the ones that attract good contributors and don't depend on the output of a single coder. It's easy to say "just make vim better" without really trying to understand Vim's C codebase.

vim's source code is really hard to test. Refactoring is needed to make code testable. That's true for every project that doesn't have tests yet. Another thing that makes it really hard to contribute to vim is that it supports operating systems that don't even exist anymore. I really don't feel like spinning a VM to make sure my changes don't break it on MS-DOS. I would rather send a PR that removes MS-DOS support than support that.

https://github.com/neovim/neovim/pull/635/files