Besides, El Salvador was able to easily sign Bitcoin as legal tender because it is a sovereign nation.
El Salvador is a democratic nation having executive, 84-member legislative and judiciary system of government. But you know that what the executive and the legislative arms of government agreed upon is what citizens will follow. El Salvador do not have the local currency of their own, they are spending United States Dollar, this could be what triggered the use of Bitcoin also as a legal tender in El Salvador. More research would have been made about making Bitcoin a legal tender in the country and the arms of government know that Bitcoin will help the country but over long time.
You even know how the executive and legislative arm of government opinion can override central bank hatred for Bitcoin in any democratic country.
I think I read in the past that the president of El Salvador passed the bill to the legislative arm to make bitcoin a legal tender which they later also accepted. El Salvador is not a sovereign nation. One of the good reasons I read that time is that even 80% Salvadorians are not having bank account, that Bitcoin can be useful for those people.
I will like to know if the Chivo wallet can be used to send Bitcoin to other wallets like noncustododial wallets, but most likely this will be possible on Chivo wallet just like other custodial wallets. What I feared most about cryptocurrencies is phishing attack, the people's personal information collected can be used later against the people. It will be very bad if a Bitcoin user in El Salvador is attacked and the attackers telling him to send all his coins to their noncustododial wallet address. I have not heard this type of attack before but nothing is impossible and it can start from somewhere. This phishing attack can still later lead to a means the attackers will successfully steal Bitcoin from the people their personal information were collected.
I think the criticism from outside is the smallest problem. It's probably more foreign institutions that have no interest in the success of crypto, first and foremost the IMF, but also the US. I wouldn't be surprised if the U.S. imposes sanctions on the country sooner or later, should the introduction of Bitcoin become a success.
About US, sanction for what? Is El Salvador building a nuclear weapon or doing what could cause damage to other countries, or is El Salvador like Afghanistan that is against human rights for women? I do not see any reason why US should sanction El Salvador when also US is supporting Bitcoin.