Those simple interfaces make programming enjoyable and don't break, so... It's enjoyable until you want to do something else rather than the default behaviour.

Those simple interfaces make programming enjoyable and don't break, so... It's enjoyable until you want to do something else rather than the default behaviour. Yes, you are in fact using the features of Rails when you use Rails. Is this actually a problem? Yes, it's terrible architecture. Your business logic should know nothing about what framework it's sitting in or which database it's connected to.