Nor did the title of this post or the actual article state that it was about atheism. It is about atheists and their response in the atheism sub-reddit.

It has to do with the atheism community on Reddit.

Even if, for sake of argument, the atheism community on Reddit is composed mostly of Vatican-sponsored trolls... it would still be a problem for atheists, because it would be giving atheists and atheism a bad name.

Which, it is. It's the dominant atheism community on Reddit. How can continued misogynist behaviour there not be a problem for atheists?