Bitcoin is valuable because it's black market money. Not because the governments allow us to use it. Ideally they don't want you to own anything that cant be controlled easily by them and force their debasement on you and surveil you. They control the law and we will never out manoeuvre them. They can just make something up to make it illegal. If bitcoin can be changed easily (it does very little to combat spam as far as I've read) it has no value as it will be coopted