Yes, I sometimes see a logical sounding but naive argument that laws should be completely free of grey area and understandable by laypersons because it would be

Yes, I sometimes see a logical sounding but naive argument that laws should be completely free of grey area and understandable by laypersons because it would be unfair to require people to conform their conduct to laws they cannot fully understand or predict. A little experience with law shows that when the “problem space” you are trying to regulate is the real world including human intentions there is no way to make things logically complete and airtight and free of unfair edge cases so in practice law is somewhat a social construct where you have to have the human enforcers interpreting fairly.