Another problem is that now your business logic is obfuscated inside the ORM layer. If you look at the structure of the source code of a typical Rails application, all you see are these nice MVC buckets. They may reveal the domain models of the application, but you can’t see the Use Cases of the system, what it’s actually meant to do.

Explicit affordances are obvious, perceptual features of an item that clue you in on how it is to be used. With explicit affordances, physical appearance and any accompanying language or text inform the user of how an object is to be used.

ts geo-metric meaning is also more obvious as the rotation axis and angle can be trivially recovered.