It is so, because the first blockchain (Bitcoin) was about Money, and that's the banks' business.
What most banks are doing now with private blockchains is only maybe using 1/4 of the full potential of blockchains. They see it as a technology for saving money and improving some internal or inter-organizational processes, which is fine as an improvement step, but not as one that will change their business.
RE: Hi, I’m William Mougayar from Toronto, Canada. I'm an investor & author of The Business Blockchain – the first business book that fully explains the blockchain’s implications on business.