I’m not even defending Ruby or Rails here. Use at your own benefit/risk…as with every other programming language and framework.
This was one of the mistakes Django made and - to their credit - got over relatively quickly. It began as a kind of imitation of Rails but they stripped out the magic pretty quickly and made it a lot more explicit.
Also my first CRUD app was very small and boring. That means un-debuggable isn't a big deal. Now apps are huge, therefore undebuggable. Even if you limit external dependencies that doesn't help internal dependencies.
You can prototype things quickly, as long as they're small, featureless, no one uses them, and you don't care how difficult the are to deploy or debug. Other than that, no problem. Hmm.