bitcoin doesn't have to be a disaster for banks at all because first of all banks are working with fiat and fiat doesn't go anywhere. it will stay around forever and bitcoin is not here to replace it either. and if you really think about it, banks are just service providers for currencies. and bitcoin is just a new currency. there is nothing stopping banks from adopting bitcoin and offer the same fiat services they offer now for bitcoin and increase their revenue.
Nope, it´s just a disaster.
SO you're saying that Bitcoin is a disaster? If so, why are you here?
a very good question ...