Now, the question: why it takes THAT long the smaller banks to go the same way and start using the blockchain?
For any company or banks to implement a new technology you need to have a thorough understanding of the system and you cannot implement all of a sudden and majority of the technology companies are learning about the opportunities of blockchain for a long time and if the banking sector find it useful for their business then they will implement it
The blockchain technology is one that should be emulate to make the banking sector easier and transparent. Though, any banks who are seeing the Blockchain as a threat has something to hid and fears accountability and transparency.
There is no way a bank could fear about its accountability because you cannot fake the credits, they might view the virtual currency as a threat but in the future all the banks will be implementing blockchain to make things transparent and convenient.