Our founders were brilliant people. Really. They were. One of the very best things about the first amendment is the idea that we get to hold each other accountable for those things we say and do. This isn’t civil or criminal accounting, but social accounting.
Before we showed the world what the value of expression is for society, people were limited in what they could say, “because it might disturb the powers that be”, or maybe they valued their head being attached to the rest of their body.
Free speech and tolerance are linked together in a most powerful way. If we tolerate bigots, for example, we will live in a world filled with bigots.
Why is this?
Not everybody does the work to properly socialize, and they won’t do that, unless they feel some need, or pressure to do it, which is the core of what the First Amendment is all about.