you keep referencing "ethical principles" like its some sort of talisman.
The Constitution in no way prohibits government from banning strikes by it's workers.
government workers have civil service protections, and thus any strike by them is illegal, if made illegal by local laws.
That is because "ethical principles" ARE the single most important talisman of law.
Your choice.
You can either have underlying "ethical principles" being the justification for all legislation, or you have arbitrary edicts.
The choice is between a democratic republic, or an authoritarian dictatorship.
Either inherent rights of each individual, or might makes right.
You still don't seem to get it.
Just like slavery was supported by legislation until 1865, lots of legislation is inherently wrong and therefore illegal.
If you choose legislation as being superior to higher ethical principles, then you are just saying "might makes right" and the government is just an arbitrary, authoritarian, dictatorship.
It is only if you support arbitrary, authoritarian, dictatorship, that slavery was EVER legal.
Similarly, it is only if you support arbitrary, authoritarian, dictatorship, that gov unions were EVER illegal.
(But that does not mean I support all gov employee strikes. Gov unions can be dangerous due to union lobbying and candidate funding.)
If I am wrong, then Jefferson, the Declaration of Independence, the American Revolution, etc., is all wrong.
Then we should have followed British law that said taxation without representation is what the legislation says.
Then the colonists then should have shut up and obeyed.
When in the course of human events, if legislation is wrong, then we all have a legal obligation to disobey that mere legislation, and follow the higher abstract principles.