> people point to open-source interactions as especially "toxic" while ignoring (or being ignorant of) the fact that things are often _far worse_ behind closed doors

Can we admit that those close doors are super toxic places then? The claim is not supposed to be that open source is the most toxic place ever, just that it is toxic. That there are close source companies that are cesspits is a fact too - but that is an independent claim.

There are also many close source workplaces where things are NOT toxic or are less toxic.