Undeterred "free speech" has a self-limiting feedback loop where the most extreme views shared by a majority of users eventually drown out minority views. Threats and insults are a kind of self moderation in communities like those, they incentivise uniformity in opinions and demographic while deterring minority/disenfranchised groups from interacting, which is exactly what happened with 4Chan. For example, as of 2025 roughly 80% of 4Chan users are male compared to, say, Tumblr's 49%

Formal moderation, while not always well done, is a way to protect diverse opinions.