Yes, but they were still the laws he placed upon His chosen people before Christ came. Laws they were actually expected to follow, whether they did so perfectly or not. Are you suggesting that God placed no actual importance on those laws and was therefore just being sadistic? I hope not.
Thus it should not be difficult to understand why some who do not believe that Jesus is the Messiah would still feel bound to those laws.
I understand what you are saying, and it is something that I have been trying to get a handle on personally for some time.