

You’re confusing two separate legal issues.
Copyright is created and enforced by copyright law.
Licenses are created and enforced by contract law.
You can violate a contract without violating a copyright and you can violate a copyright without agreeing to a license. You can also license works that are not able to be protected by a copyright because they are two separate categories of law.



That is the FSF’s position, but the case law has examples of cases where it was allowed to be treated by a contract.
SFC v. Vizio, the Software Freedom Conservancy sued Vizio as a third-party beneficiary of the GPL as a contract, and the court allowed the case to proceed on that theory.