[shijie]

I would say that with SO, amortized consensus is fine due to there being a "right" answer to a technical problem or question (more or less). Twitter deals mainly in the market of human opinion, which is necessarily far more nuanced with n sides to a story. This makes Twitter the arbiter of truth for their platform. Perfectly legal, as it's their platform, but I wouldn't expect a free exchange of ideas on such a platform.