Laws can be made in any way they like. The argument is not in how laws can be made, but in whether they are any good. This is an argument about quality and usef

Laws can be made in any way they like. The argument is not in how laws can be made, but in whether they are any good. This is an argument about quality and usefulness of law. As Knuth puts it, "Man-made laws can be significantly helpful but not when they contradict fundamental truths.". You are right that the method for deciding on what parts of math are subject to patent can be wholly external to maths and not pay any attention to mathematics whatsoever, however what Knuth is saying, and I would tend to agree with him, is that this would be folly.