Why do we think that people organizing violence on Facebook is Facebook's fault? We don't think it's T-Mobile or AT&T's fault when people coordinate via SMS. We don't blame Samsung or Apple for selling them phones. Why is Facebook being singled out for not being an effective enough pre-crime censor?
Facebook is not being singled out. Look what happened to Parler. It is probably worse in terms of Parler since Facebook and Twitter were used to coordinate the capital riots and Parler was just the scapegoat.
I think "can this service be used, in a pinch, to attempt to overthrow the government" is going to be my new metric for safety in evaluating online services.