Why is free speech free? If you think people (and by extension businesses) should be allowed to express themselves that's one thing, but advertising is importan

Why is free speech free? If you think people (and by extension businesses) should be allowed to express themselves that's one thing, but advertising is importantly distinct from that. It's protected speech in most of the Anglosphere to say you don't like some person or group, but not to maliciously damage someone's reputation or incite hatred. I can imagine an analogous situation where you're free to express that you think your product is good, but not to incite irrational desire in consumers or try so place information about your product in places that are difficult to avoid, like public billboards.