A scarey thing about cultural movements is how they take the law with them. A system of law is only as just as its layers judges and juries.
Responsiveness to cultural norms is in part a function of courts having to maintain some minimum level of perceived legitimacy with the public.
To make the law more predictable, a notion of 'precedent' is used to help make future interpretations adhere to past ones, lending some continuity to all this. But this means that an interpretation of a law in a new context can partially determine what that law means without modifying the text of the law.
Abandoning the notion of precedent might avoid that, but it just makes the law unpredictable in other ways.
The way I interpreted your post was that you were saying a law should just be changed by the whims of the populace without a proper process in place.
But I think that element of consideration of popular feeling or shifting cultural norms is important. It's what lets judges do things like pass over laws banning women from wearing pants as a form of crossdressing instead of requiring, or to reinterpret language about equality as extending to wider groups of people than originally intended.
Laws should not impose morality.
We often pretend they are different, or draw a distinction between behaviour constrained by laws and that constrained by personal morals, however the question of what laws to create and how they should be formulated are moral questions.
Although actually neither the right or left hand side rules are arbitrary. They were each intended to better serve a moral objective.
https://www.historic-uk.com/CultureUK/Why-do-the-British-dri...
I'm not sure we need to reduce all norms to 'morality'. But if we think of morality in a really broad way, like 'humans (or other sapient creatures) seeking to satisfy preferences or impose additional structure on nature or society for their own purposes in a universalizable/principled (i.e., fair) way', then definitely: laws should always be motivated in some way by morality.
That's different from the claim (which I'm not saying you've made) that this relationship means that laws should always simply 'encode' moral norms in some direct sense, which imo is a common (and mistaken) simplification.
But yeah I think we're on the same page.