Here are some adjacent concepts. It doesnt matter what the majority wants on concepts like "banning hate speech" not when hate speech can be formed to become - literally anything you dont like.
If thats the case, you are infringing on minority rights and something has to fence you in.
The entire deplatforming thing is so dangerous, because it leaves a majority with the believe, that diverging opinons can simply be "turned off", while raising anger and outrage forms in fringe groups. People not being able to talk to each other, because - someone can always produce an activist that feels triggered, is actually dangerous for society.
Also, those limitations arent there to protect. The majority doesnt have to be protected from minorities. People don't have to be protected from speech.
Whenever speech is limited or restricted, this is because of political motives, or because of situational aspects (impending danger for life, health, ...).
The why is very simple as well.
Meaning gets created through attribution. So if you have a majority being able to decide what constitutes meaning, and also be able to cast people out because of it - you end up with group dynamics, and not anything akin democratic systems, where there is a balance of power.
Thats basically why the concept of free speech exists.
Also there is a current tendency with people advocating against cyber bullying, to be rather free with their opinions on what would constitute "violence". They bring things into this context, because violence is something we have to protect people against, as a society.
But there is a flipside to this as well - if you enlarge the classification scheme of what entails being on the receiving end of violence to the point, where this can become subjective. Then also concepts like "non violent protest" become subjective - which in return makes the concept useless. So its always a thing where you have to weigh minority rights against what a majority would go with.
As a conclusion, forms of speech, can never be defined as "violent", "harmfull" or "hate speech", ad hoc - this always has to venture through a formalized process, where an independent entity also looks at minority rights in return. Some forms of speech can still be categorically banned, but the majority is not the decider.
And the second point, repeated was, that people dont have to be protected from speech. When speech is limited, it is usually because of considerations that have nothing to do with the individual.
(There are some exceptions, f.e. where peoples professional reputations are affected.)
Now - in a code of conduct, you can write basically anything you want - and you can then penalize people based on that..
But thats different.