It's a matter of whether someone is using HN as intended or not (as far as we can tell). For accounts that repeatedly go against the intended use of the site, we don't have much choice but to ban them, or else the site won't survive for its purpose. We do warn them first, often quite a few times and over a long period before banning—it depends on how much history the account has here. For accounts without much history, we sometimes ban straightaway, if the violation is egregious.

That doesn't seem excessively authoritarian to me and I don't see how we could do it differently without giving up on the site's mandate, which is not an option.