I mean - you can opt-out of choicepoint and Lexis-Nexis, and CRAs are private company databases, so in theory you should be able to "opt-out" alltogether if you are some ultra-wealthy private person that doesn't want a credit file, right?
The only way to not have a credit file is to not use credit. Somewhere in the terms and conditions that you agree to when you sign the loan papers you gave the bank permission to report on your account to the credit bureaus.
Opting out doesn't keep you from having a credit file. It keeps you from getting unsolicited offers from companies that you don't do business with. In other words, it keeps them from selling your information to companies because you meet certain requirements. Any accounts you have will still be reported, and companies you do business with, employers, etc. will still be able to pull your file.