Re: Government should implement blockchain technology to prevent corruption.
But we can't expect a corrupted government to take steps for anti corruptions. 
As you said the blockchain can be used in all the transaction for the government related which can help us to have corruption free transactions but the politicians need to implement this system but if they do then they can't make money anymore so they will never do this.
LOL, as expected for the politicians then you are right they should never implement this kind of system because they could no longer earn from their corruption activities. However, If only I am a leader (A president be like) then definitely I will implement a system like this for every public servant employee on doing transaction which involves money. As you said the blockchain can be used in all the transaction for the government related which can help us to have corruption free transactions but the politicians need to implement this system but if they do then they can't make money anymore so they will never do this.
This is the main reason why government do not implement block chain or bitcoin in their countries. If blockchain is deployed, it would be almost impossible to do the corruption by the politicians especially for the underdeveloped countries. People should force the government to implement block chain to minimize corruption.