Freedom of speech is not the freedom to say what no one objects to. It is the freedom to say what is objectionable, what others would prefer remained unsaid, to say what is controversial. A Constitutional Ammendment that only guarantees the right to say that which no one finds objectionable is empty, useless text.
You're right. I'm back in school after a 15year hiatus, and many in the current generation raised in political correctness actually believe that speech they deem "offensive" should be barred.