When you have someone like pewtiepie or whatever his name is not only disabling comments but months later saying his health is better for it. It's to easy to say your wrong. He might be an annoying douche but he is a beloved annoying douche to a lot of people and even he had enough with Youtube comments to the point it was affecting his health.I agree that Youtube can be and often is a cesspit.
Unfortunately though, there many popular, more subscribed, and dare I say more "controversial" individuals who post often divisive topics on their channels, and their ratings and comment section remains open. As much as I personally don't usually care for his style, one of Sarkeesian's bigger critics, The Amazing Atheist, has kept his comments and ratings open, and made it a point to address the more coherent arguments against him or that may come up in video responses.
Its to easy to why someone else who happens to be dealing with a very charged topic might not want to deal with them and find a better neutral ground to debate on. That said Anita doesn't seem to want to actually debate anything. It's a fault that will actually hurt her and her goals in the long run because by the end when she runs out of valid points she will keep going and by the end she will be another Jack Thompson.
Now AA on the other hand is nearly a professional contrarian. Unlike most people he can brush off most of the attacks. But he actually gets a kick out of debating and could go on and on without traction's on any debate. Even one as simple as the best cereal. Eventually causing the other party to give up. Someone doesn't have to love debating in an attempt to bring to light an issue they have. Youtube comment blocking is not a valid complaint against Anita.