The underlying premise of that Tweet is that people willing to kill when other people offend them means it should be illegal to offend them. The obvious result of this that any group which wishes to not be criticised merely needs to kill people until criticism of them is banned. It is in essence a justification of coercing one's fellow citizens.I disagree with this fellow: I think free speech is absolutely worth a civil war. Most rights are, if the alternative is losing them.
As for rights, I like them, and I don't want to lose them, but I think the reaction to their limitation also requires proportionality. Rights can be restricted in small ways that don't necessitate reactions as strong as revolution. If rights of free speech are higher in the USA than Germany, for the USA to decline to German standards would hardly be such an intolerable loss of free speech that it would demand a country convulsing into civil war, because free speech in Germany is patently extremely high.