Morally, laws could be good, bad (evil), or neutral.
An example of a good law would be one that makes murder illegal.
An example of an evil law would be one that mandates segregation of people based on skin tone - in other words, mandates racial segregation.
An example of a neutral law would be one that bans a harmless, or mostly harmless, thing. Think of the partial prohibition on alcohol (illegal for anyone under the age of 21, at least in the United States) or, for a contrived example, banning people from wearing a wristwatch on their right hand.
Defining whether a law is good, evil, or neutral can be subjective. Subjective here meaning that people generally can’t agree if the law is good and just. Banning abortion is an example of a (potential) law that would be subjective - some may argue that such a law would be good, while others may argue that such a law would be bad.
The point of this post isn’t whether a given law is good or bad, but rather that neutral laws are not truly neutral. Rather, a law that could be construed as neutral is instead bad.
Laws must be enforced; for the point of this post, anything that cannot be enforced (such as the US Flag Code) is not a law.
Enforcement of a law can be as minor as a citation - a “slap on the wrist” - or as major as death. This issue with enforcing the law is that resistance to the law can ultimately end in death.
If someone gets fined, and they do not pay, they can be arrested. If they resist getting arrested, then the force used to attempt to arrest them could result in their death.
Should someone be fined for wearing a wristwatch on the wrong wrist? Or drink alcohol at the age of sixteen? If they are unwilling - or unable - to pay the fine, should they be arrested? Is the risk to the person being arrested - not to mention the person (or persons) doing the arrest - worth the enforcement of such a law?
I argue that it is not. Therefore, any law that could conceivably be considered neutral is not truly neutral, but instead a bad, unjust, and evil law.