you are confusing the blockchain aka the technology with bitcoin aka the currency build using this technology. the banks (some of them at least) see bitcoin as the competition and are scared of it, some others see it as an opportunity to make a lot of money by offering new set of services in the near future.
the blockchain technology however, is different because that is what they can use to build their own currency, and also use for a lot of other things that this technology lets them do.

in short when you hear some bank is considering the blockchain technology they are not talking about bitcoin.