One day they will accept. It's just a matter of time now. The first steps towards adoption they have already done. For an example, banks in my country offer Bitcoin as investment alternative, although you can't access your Bitcoins directly, without using the bank. However, it doesn't have to be like this forever. Soon I believe they will become less strict, allowing customers to deposit and cashout their BTCs to external addresses, although some kind of KYC must be implied along the process.