I think if they weren't rationalizing they would explain the concept as is - its a wrapping coordinate. I do agree they understand what is happening low-level and that it is a wrapping coordinate. They still choose to use this parallel universe explaination for ease of understanding and explainability to outsiders. A rationalization is just "the action of attempting to explain or justify behavior or an attitude with logical reasons, even if these are not appropriate" which sounds exactly what the PU explaination is. There is no derogatory insinuation or anything involved here.