It worked as long as nobody was trying to go after it. That's been changing and as we've seen the parties involved have plenty of real-world presence which various authorities have been able to take advantage of. This is why the absolute claims about “free speech” are simply reflecting a deeper misunderstanding: it's true that nobody can stop you from making a Bitcoin transaction unless they block the protocol entirely but the retroactive consequences deter people quite effectively, very similarly to how to even very authoritarian states can't prevent you from saying something in public but can very effectively make it too risky for most people to do.

> Free speech laws work even if Facebook deletes your post, or you a fired, or sometimes someone doesn't appeal their conviction. Your argument about "miners, developers or exchange operators" existing is not any more valid than this one is.

Free speech laws generally don't apply to private companies like Facebook, who are generally given a high level discretion for how they choose to run their communities. The same is true of a blockchain network: the implementers and operators set the policies and since these systems are based on money that generally means that you're getting the rules which the major players either want or are required to implement by the governments with jurisdiction over them. That last part is key to understand: maybe a protocol allows you to make a transaction somewhere but the cost/risk shifts considerably if the recipient knows that they won't be able to use it in most places and every potential buyer can easily tell that it's on a list of tainted tokens.