I can only speak for my own education (in the UK) where free speech wasn't really drilled into me as a valuable right, and as such I can understand why people don't understand its importance. Topics like this fall into what in the UK is categorised as PSHE (Personal, social, health, and economic). Unlike other subjects, it was not a GCSE meaning that there was no exam to be taken, and you would not receive a qualification at the end. As such, it was often given the minimum amount of time the school could possibly allocate on the timetable. There were no specialist teachers for the subject; teachers of other subjects would have to teach it. And come to think of it, I was seldom taught about some of our most valuable rights like our right to free speech, our right to a fair trial, and our right to vote.
When it comes to free speech, many hear speech they deem to be abhorrent, and thus their reaction is that it ought not to be legal to say. And this feeling is understandable but perhaps demonstrates that the individual has not been educated on why to value freedom of speech. They often do not understand how dangerous it can be to allow someone to decide which speech can, and can't be allowed.
Additionally, I have been reading the book Fake Law, and what I have found striking is that large parts of the public are completely uneducated about the law, and why access to justice is important, and I myself learnt new things from the book. But the book also demonstrates how the media, and in turn politicians exploit this lack of education to slowly take away our rights, and restrict our access to justice. And this makes me reflect on my own education, and I now wonder whether that was intentional.