noun
Synonyms of legal tender
: money that is legally valid for the payment of debts and that must be accepted for that purpose when offered
(I've bolded the important part).
Oh wow. Thanks for the reference. I do not believe in myself. I would argue with you if did not provide the reference. I am still in a confusion and want to discuss this further. In the USA or whatever country wants to adopt Bitcoin as legal tender, they have to wait decades until 100% of people understand how bitcoin works. Because, when you make it legal tender, They must have to accept the payment method when offered. Imagine a guy never heard of Bitcoin and you offered him Bitcoin to buy something. If he denied to accept it, is it any law or rule violation? If so, we have a long way to go.
To elaborate just a bit further, and if I am not entirely mistaken here, even the merchants doesn't necessarily have to know that you paid with crypto as there is a middlemen in the backend providing the infrastructure for instant conversion of your Bitcoin into the appropriate amount of fiat currency that the merchant is asking. This means that you are essentially paying the equivalent of Bitcoin to the middlemen in the equivalent amount of fiat currency that the merchant is asking the middlemen for to settle the transaction.
Everyone would still be free to choose. If someone has no idea what Bitcoin is, that someone is also not going to settle taxes in cryptocurrency. But those who are mainly dealing with cryptocurrency would now have the choice to do so.