I suspect you're aware that your rhetorical question rather neatly makes the point that taxing in crypto would immediately (and for crypto-bros, ironically) imbue them with value.
What’s the point you’re trying to make? Do cryptocurrencies have value or not? It’s one or the other, you can’t claim they have value when you want to tax them and then claim they don’t when you want to regulate them.
I’m not asking you to “give” my money value. I’m asking you to answer a simple yes or no question: does it currently have value or not? The way you’re trying to defend your obvious lack of consistency is purely circular. If it has value, you tax it. You can’t say that if you tax it then it’ll have value that justifies taxing it the first place.
I think your difficulty is in understanding what states hope to achieve by taxing, which is not in order to capture some "value" from the thing being taxed. To them, crypto obviously has no value beyond anything they can do with the crypto (i.e. none). On the other hand those that fall under the tax jurisdiction of a state have a tax liability and whatever unit they can satisfy that liability in has value.
The fact that states can't issue more crypto on demand is why they'd be stupid to ever pay attention to it, much less let people pay their taxes in it. Crypto is not even money in the sense that it doesn't represent a debt, which is where the value of money is derived from.