When you make specific methods illegal, it tends to lead to loopholes. If you just make the result illegal then nobody can try and get around it by using a slightly different system design.

Also true.

But which way around does that apply? Racism is a concrete example of what AI may incorrectly automate, it's not the only bias that AI can have — any correlation in the training data will be learned, but not necessarily causation — and the goal of these laws is to require the machines to be accurate, unbiased, up to date, respectful of privacy etc., with "not racist" as merely one example of why that matters.

(Also the existing laws on racial equality were not removed by GDPR; to the previous metaphor, the fence being better doesn't mean you can fire the ambulance service).