Let me guess: you've never actually been credibly threatened with serious violence? You're basically thinking like a "crunchy mom" anti-vaxxer who thinks that

Let me guess: you've never actually been credibly threatened with serious violence? You're basically thinking like a "crunchy mom" anti-vaxxer who thinks that measles are harmless because she doesn't know anyone who's died from it. Imagine for a moment that you're a black person living in 1920s Mississippi. You personally know people who were hanged by lynch mobs. You've read about Mary Turner who was burned alive while 8 months pregnant for daring to speak out against the lynching of her husband. And now white people tell you they'll kill you if you register to vote. You seriously argue that banning those threats would be a worse infraction on people's freedom than allowing them? If you don't see a way of defining hate speech in a way that won't be misused any worse that free speech is, it just means you haven't thought very hard about it, and suffer from status quo bias.