I don't think you mean all people... because in the same sentence you advocate harm (or the de facto threat thereof) to some people based on what they might say. So is this hurt feelings? Actual physical harm (or the fear thereof)?
Or are you suggesting that people should be free only to say those things within some pre-approved range of ideas of which people like-minded to yourself are prepared to tolerate?
To be specific, if you're saying that any person that would advocate physical harm, or cause a reasonable person to be fearful of physical harm, should be prevented from speaking... then I'm likely with you. If you really mean more than that, then "hell no!" back at ya.
On the other hand, if you shout "fire" in a crowded place, you make yourself responsible of causing a dangerous situation. Same as flying a drone over an airport or throwing stones from a building.
You can see parallels with white extremists that write racist screeds, and later go on to commit violence themselves, or when their writing inspires violence. One former white supremacist who was the leader of a popular white supremacist punk band admitted he knew there were people who committed violence and quoted his music as an inspiration, which in part helped him leave his old views behind.
To paraphrase Bob Dylan, music can't keep a revolution going. But it can and does encourage people to act.
And I am not meaning just "controversial" social/political views - for example FPS games were often tarred as "violence inciting" with little to no evidence just 15years ago. In current framework, that would be enough to actually ban them. Do you really think it's a good idea to go down this rabbit hole of banning anything that "might" lead to violence one day?
Does it mean we should ignore dogwhistling? Honestly, I don't know. It's a really hard problem I think. And current "solutions" of deplatforming "extremists" don't seem to be working towards reducing actual violence / social tension, so I don't think it's the right approach.
Do we philosophically want to live in a world where people can be incited to great amounts of violence just because we want to protect FoS on private platforms?
Do we want to live in a world, where everyone will be scared to say anything socially unacceptable (because it _might_ lead to violence!) because of the total deplatforming that might happen as a conseqence?
There is a lot of blurring around the definition of "inciting violence", and I am scared of the slippery slope too.
I want to live in a world where anyone is free to say any stupid idea they want, and anyone else is free to correct them or ignore them or do whatever they like.
Actual harm/abuse/harassment should be illegal of course, like the kind where a person is physically doing stuff to another person against their will.
But if blocking a person on twitter is all it takes to avoid "harassment", maybe that's the best way to deal with that.
This is not about "weird people with quirky ideas". This is about people who use speech to abuse, cause harm, intimidate, harass, or inspire others to commit such abuses. This cannot be tolerated in a society that wants the right to "Life, liberty, and the pursuit of happiness."
One can always find a non-abusive way to present an idea. But when they cross the line into a form of abuse or violence, they should be stopped.