Look, instance admins can block whatever they want for any reason they want. It hurts your users but do you. And I'm not trying to argue that Facebook isn't a fucked up company. But actively working to discourage extremely skilled participants (and love them for hate them, FB engineers are VERY good) from contributing or associating with your open source protocol or community is just peak stupidity for people who claim in the same breath to want to remake and reset the social web.