It looks more like the dev felt the PR being introduced was purely for political reasons, which he disliked. I'm not saying I agree with the dev, but you've stated he "had a public freakout over the idea that women exist" and that doesn't appear to be the case here.
Consider that claims like yours, and the responses to his rejection of the PR, probably only strengthened his belief of the PR's intent.
Docker enables you to create instances of an operating system running within a “container” which doesn’t access the host computer unless it is explicitly requested. This is done using a
Dockerfile, which is a file that describes in detail all of the settings and parameters for said instance of the operating system. This might be packages to install ahead of time, or commands to create users, compile code, execute code, and more.This instance of an operating system, usually a “server,” is great because you can throw the server away at any time and rebuild it with practically zero effort. It will be just like new. There are many reasons to want to do that; who doesn’t love a fresh install with the bare necessities?
On the surface (and the rabbit hole is deep!), Docker enables you to create an easily repeated formula for building a server so that you don’t get emotionally attached to a server.