Banks always want to maintain their repatriation in the market. And the bank knows that many users in the Bitcoin market will want to join the Bitcoin and leave the Bank.And the bank cannot be more solid and secure on any day, so the bank does not want bitcoin in the market. !!
Though they know that there is a huge market adoption towards crypto but they know already that people will still be using with their services anytime. Banks aren't actually against crypto, indeed, they are trying to adopt the system and make benefits by then. Banks will still remain of what have started and just open for another room for cypto adoption and not by closing the opportunity given with to the community.