Because it is technologically impossible to enforce this on the owner class. The people who control compute control the rules. Without proper audit trails it becomes impossible to prove or enforce.

The only ones, then, who could afford to break the law are also the ones who make the law and own the law. Everyone else is subordinate in that model.

That's why technology like watermarking doesn't work and will never work. Implicitly it creates a minimum of a two-tiered society and no amount of "law" will change the technological reality of this.