If I understand you rightly you are saying that the copyright subsisting in maps (in countries such as the USA) is only in such creative element as the map contains. A consequence of that would be that it is not infringing copyright to make a copy of a map, provided you only copy the factual data and not any of the creative part. In other words you could buy a tourist map of New York City and trace over it to extract out purely factual information such as street layout, and make your own map provided you didn't copy the typography or colours or recommended restaurants or other creative element.
If that is the case, then I thoroughly agree that doing the same process using a computer and a computer-readable representation of the same map would not be any more copyrightable.
However I don't think it is the case, because maps are explicitly covered by copyright law, and I don't believe this coverage is hedged with anything like 'but only the creative part, not the factual part'.
I don't mean to imply that making a map of an area grants an absolute monopoly over the facts it contains. Anyone else can go out and independently survey the same area. But I don't think they can simply copy the map somebody else produced, even if they just copy the facts such as the position of objects or their names. If that were so, then all maps would be pretty close to being in the public domain, and projects such as OSM would be either unnecessary or trivially easy to complete by copying from existing maps.