100% this. To say that the author of the post — whose job includes knowing whether women and minorities feel particularly unwelcome or not, based on actual data and talking to them — must have invented this point is rather outlandish. Based on what?

An online community can’t possibly be less welcoming to women, for example... because it has screen names? Because people don’t express open disdain for women like they do for newbies? You don’t have to be an expert on this stuff to know not to rush to hasty conclusions, especially in the face of evidence.