Banks disapprove of the cryptos because altcoins are made to resolve all the flaws and negative sides of Banking system. BTC is everything that the standard banking system is not and vise versa. If the banks make their own coin, it will still have the same core and algorithm as any altcoin. I believe that they will simply adjust it to be suited better their needs and goals. I don't see this as a bad thing, I see it as a compromise to make BTC easy access and more approved and used by the masses. This is a support to BTC by the banking system, in a way. I believe that it will be a good step forward.