This is not a difficult thing to do, but the government's are only not interested in this because they cannot control it the way they would control the issuing, printing and regulating of fiat currencies. Whether bitcoin is made a legal tender or not, I don't think it is restricting anyone from making payments with bitcoin as long as both parties involved in the transaction have mutual understanding.
Countries now are becoming more bitcoin friendly, you can do what you want freely with like minds, but do not expect to hear from the government anytime soon that they are going to enact a law enforcing bitcoin on everyone as a means of payment.
This should not bother us much, even the Bitcoin community are populated with Bitcoin investors, traders and business people, not genuine people who want to do everyday payments with bitcoin.
An observation of the case of El Salvador and Central African Republic shows that making Bitcoin a legal tender is not as easy as some of us thought.
For citizens to embrace Bitcoin there should be intensive awareness programs aimed at enlightening the people. The government should also ensure that all the necessary infrastructure that will make Bitcoin transactions successful are in place. CAR couldn't achieve these first two steps.
There are also other external influence from powerful nations and organisation. Some of these institutions are anti-Bitcoin and will want to frustrate the project. This was the case of El Salvador when IMF forced it to review it's Bitcoin policy.