Wrong, bitcoin is not centralised but it's opposite of that. Bitcoin us decentralised which means no other 3rd party can alter the bitcoin network and government could also can't impose tax on bitcoin. All I know is bitcoin is automated and no one can change the system.
Yes, Bitcoin is opposite to centralized always because no has any authority on bitcoin, that's why it is called as people money. Governments are not accepting it because they cannot control the bitcoin and transactions.