This question is asked and answered all over HN, any time a debate touching on "free speech" comes up, including the current top-voted comment.

Independent of that: what crosses the line is nowhere like settled. Many people like to act as if what they find offensive must obviously be treated as if it were beyond the pale. They're probably living in a small filter bubble where the speech in question is unquestionably offensive. Their views are rarely majority opinions, however.