I think the point is more, "you can't legislate holding those values".

Laws are informed by the interests (which may include morals) of the law-makers, and many people do base their morals in part on what laws exist, but most people believe that at least some laws are immoral, and some immoralities are legal.

Many law-makers want people to view illegalities as immoralities, but that's not how most humans operate.

The goal is the society by and large keeps those values as a whole. The values inform the laws and lead to a certain result that, in theory, reflects the value (politicians decide murder isn’t ok -> murder illegal -> fewer murders -> society now, in effect, broadly reflects a people that don’t think murder is ok). Whether people “buy in” is a different matter and is less material, though given enough time laws can cause people to shift culturally (morally, ethically). A society with lax rules on dumping trash will likely lead to more people not caring about the ethics of it over time as legal permissibility can lead to shifts in what we think is morally ok.

Much of Western Europe/Scandinavia has a stronger renewables culture than the US, for instance, but a lot of that was originally (and still is) driven by necessity. Fuel is more expensive, they don’t have as much space to dump things or build, etc. so they need to be more efficient which has also led to a “green culture.”

Laws and culture/morality/etc. aren’t as independent as you think IMO