the main reason for not implementing crypto currency and bitcoin as a legitimate currency is money laundering and high volatility in the currency. maybe they understand the serious advantages of crypto-currencies, but they are not yet ready to implement these functions in financial and banking systems.
You really do not need the banking system to implement the currencies but i am sure they will be implementing the blockchain technology in the future for each and every transactions, pointing out money laundering as an issue is not a valid reason as fiat currency is used more for those sort of illegal activities and that cannot be said about bitcoin as everything is recorded.