This hack is a very, very good example of why KYC/AML rules are a bad idea. When you have these centralized storehouses of sensitive personal info on millions of people, it's only a matter of time before a skilled attacker gains access.
Decentralized exchanges and free access for everyone - absent selfies that require customers to hold up their passports next to their faces, colonoscopy reports and credit checks - is the only way to go.
You can thank terrorists for that, since banks were relatively free with servicing customers until 9/11. After that, the governments all over really started to reign down on where the money is going and how its being spent. A lot of developed countries these days have their own kyc/aml regulations for their banking system.
And it doesnt help that a lot of companies invest very little money into their IT Security either.
It doesn't really matter how much money they invest in IT security anyways. With that much valuable info in one place, even inside jobs become profitable and likely.
Centralized data storage systems can't really be secured in this day and age.