Yes bitcoins are non reversible and we can set the fees as per the urgency of confirmation needed and hence they can be use widely just sometimes confirmations are slow moreover we still are not accepted at big sites.
With that system bitcoin has, it does not fit to what government like in our online transaction, they want to control things to ensure that we are doing it in compliance with the law. Bitcoin is only the future money of crypto currencies enthusiast but in general, it is not effective to implement it for the benefit of all. Legal tender is what people need as our trust in our government is still bigger compared to our trust with bitcoin network.
The Government won't be too unhappy with Bitcoin, because it leaves a trail. It might not be controllable, but in case of any wrongdoing, the blockchain is a permanent, immutable record.
the government will have to accept the importance of bitcoin, they have to respect the people interest and have to provide facilities to the people and bitcoin is really providing online buying and selling facilities to the people.
I don't think that any government will accept Bitcoin officially.
First, they have to work according to international financial laws and regulations.
World financial institutions know that Bitcoin is decentralized and can't be regulated or controlled.
Because of it, they will never officially accept Bitcoin.
Because of this, it's not possible that any single government officially recognize Bitcoin.
Bitcoin will remain as alternative, virtual way of payments but merchants, which accepts bitcoin, will have to transfer all results from bitcoin to ''hard currency'' accepted by authorities.