What's a good bank customer? Somebody who uses the bank for all their financial needs. If you have a savings account, checking account and a car loan, you're gold. If you also have a credit card that you use, even better. I'm afraid the people who have a "free" checking account and that's it are not exactly the most profitable customers. Unless they routinely overdraft their account and keep paying the high fees, that is.
Seriously, it is all about making a profit. Banks charge $30 a pop because they can and because people will pay it.