Trust me, it's not their preference either… in order to keep from being blacklisted by the OECD, though, banks have to resort to this level of bureaucracy. They're called "Know Your Customer (KYC)" rules, and the idea is to over-collect personal and financial information in order to determine that a bank customer is not a terrorist.
Anyone with half a brain can see that this is one of the stupidest notions in the world. It's like locks on a door– if someone wants to break in, a pithy little lock is not going to stop him. Similarly, if a "terrorist" (I hate even using that word) wants to open a bank account, an avalanche of paperwork is not going to stop him.
As an example, I would point to accused arms dealer Victor Bout who currently sits in prison right here in Thailand; Bout was placed under US and UN sanctions back in July 2004, and yet he was still able to register numerous Delaware companies with bank accounts.