OK, I'll bite: can you give us some ideas on how this would lead to a genuine advancement in user authentication (that we wouldn't have with username/pw de-linked)?
EDIT: Just to be more precise, there is a correlation here, and with so much data a lot can be known. Patterns can then be forbidden from password fields so the website is less prone to dictionary attacks.
Is it pointless to reduce the attack vector against your website?
And, no, for a banking system, it is not that user-hostile to say things like "we have found that using <pattern> in your password makes it easy for people to guess, please choose a more complicated password".
Username: mickael
Password: mickael69
EDIT: Just to be more precise, there is a correlation here, and with so much data a lot can be known. Patterns can then be forbidden from password fields so the website is less prone to dictionary attacks.