I think it makes more sense than the alternative? It's an acknowledgement that, while some of the proposed terrain can work thematically with the rest of Frontierland (e.g. the rockwork, the streams, the trees, the geysers, the lodge-like structures), the actual content cannot as the cars themselves are completely anachronistic. That is not to say it is well-designed, better than the river, or whatever, but thought was given to the surroundings. While they should've just picked something that worked without hiding it, I prefer this approach to what others proposed with a Radiator Springs copy that would have been fully exposed to other parts of the existing land.