I don't think this is a subjective matter? The sequence of events was:

1. async feature was proposed in 2014 and earlier, Bram was opposed to the idea in general

2. neovim was created to integrate async and other improvements

3. lots of plugins started supporting neovim's async

4. vim comes out with its own async feature

You're welcome to ask Bram what motivates him personally, but I'm comfortable with my judgement of causality to the ecosystem as a whole.

> Neovim fans seem to hijack Vim discussions frequently. Sometimes people want to talk about Vim.

You may talk about vim, that's fine. Do you feel neovim is off-topic for vim discussions? It seems fairly related to me.