Exactly. If one has something -- food, clothes, money -- and it is taken without his consent or due process, it is theft. It always was wrong and always will be wrong regardless of what the law says.
On the other hand, if one has something and one wants to give to someone else it is only "theft" if the law defines it as such. Once the law is changed nobody can call it "theft."
And if the law is unenforceble or fails to make sense to the average person, it is not going to be obeyed anyway.