Why shouldn't I when Lemmy, a relatively educated selection of hyper lefty nerds with various mental illnesses is shitting itself in a self-righteous fury at the idea that they might be indulging in eugenicist and ableist thought?

Ignorance seems like a pretty reasonable assumption to me.

It doesn't seem reasonable to assume that everyone knows everything and it's therefore socially unacceptable to bring it up when on the topic.