I assume she thinks that Yann has enough intellectual capacity to improve situation of biased ML but doesnt execute. Further, my guess is that the reason why he doesnt execute is not transparent to her, hence frustrating.

Dr. Gebru, among others, expects and insists that they do go beyond that and try to get involved in the social consequences of tech. They refuse, ergo conflict.

Yann has no obligation to do so on Twitter, and shouldn't be called out by coworkers publicly regarding that decision, in my opinion.

Yann was talking about a specific model, she was talking about ML & society on a grand scale. Can't we talk about specific things now? Why did he have to apologize for it?

My feeling is that Timnit is using people, she guilt trips, humiliates them online, makes a big fuss and it's all to whip up support in her crusades. She wants to win the public opinion by any means, so she needs famous opponents to pile on, such as Yann and Dean (who have universal admiration in the field). She's always playing the victim. I find this kind of behavior toxic, it degrades dialogue.

Isn’t Gebru an “AI researcher”, after all?

Every practitioner already knows that these models behave according to the data they are trained on. The general public has no use for this explanation because they aren't the one deciding on the training data. So the only practical purpose is to offer some superficial causal mechanism that sounds like an explanation to that public, presented as an unchanging fact of nature, and distract from the equally true fact a biased model is only published or used iff it is trained on biased data and someone decides to go ahead and publish/use it nonetheless.