remember one thing; banks will do business as they always did, while exchanges advance preventing another disaster.
As a matter of facts this is quite untrue to compare both of this. Banks and exchangers serve a different purposes as banks are meant to "keep your money" ( and use it to lend another people and get interest from it ) but exchangers arent meant to be used as a platform to secure your coins. No matter how secure an exchanger is people still shouldnt be putting their coins there to "secure" it.
Another note, banking system is an old fashioned system that seems couldnt be undergo anymore improvement. These banking system may varies throughout each country however all of them are pretty much the same.
Not only the exchanges, but the users have also become smarter.
Not everyone, traders still loves to store them at exchanger because it is much more convenience that having to move your coins back and forth each day
the exchanges have introduced new security measures
Are you pointing this to multisig? I doubt that many exchangers are using this already