Nnnnnno, it's not "just words". It's
threatening to kill and rape people, directly attacking their safety and their right to a peaceable life. It's giving a platform to people who are putting the idea in others' heads that
they should hurt and kill people. I don't have to follow the "race realist" assholes among us to have the fact that they are given a platform by a company under no obligation to do so--and that they use that platform to gather followers under the direct purpose of separating the white race from the blacks or the Jews or whoever the hate-object-of-the-week is. Their followers do. They are strengthened by being given their platform with which to attract more soft-headed followers. Words have consequences that cannot be waved away so cavalierly. Those consequences may not impact
you, but they impact a whole lot of people and they can't be dismissed.
The government should, for reasons that make a lot of sense, be reticent (but not wholly unwilling, because the real world doesn't work in absolutes) to intercede here, because freedom of speech with regard to the state is a different thing from respecting and accepting speech by society--but Twitter isn't the government.