I get what you're saying, but that raises an entirely different ambiguity vs the states where it is illegal but decriminalized. Because you'd have to lump them all in together at that point, defeating the purpose of differentiating between the criminality within state law.

Just look at the difference between New Mexico, Texas, and Louisiana for instance. They all treat marijuana differently on a state level but they'd all be painted one color under the logic of federal acceptance and lose the nuance of how it's handled in actuality.

And besides all that, the vast majority of cases where someone is brought to charges in the US defer to state law precisely because the fed doesn't have a standard. The only time the US tends to step in is for felony level cases or interstate crimes.

But when you have dispensaries have large signs and even highway ads and pay taxes, it is not just “unenforced”, it is for all practical applications, legal