While designed to make things easier for newcomers -- I think these features are actually some of the biggest culprits in making things _harder_ for newcomers, because they fail at so many edges, and when they do fail, there's so much magic going on that it's nearly impossible for a newcomer (or even an intermediate user!) to figure out what's going on and why. I think the heavy emphasis on auto-loading was a mistake…
The idea that Rails was designed to be accessible to newcomers seems to be pervasive but I don't think that has every been a top priority for the project. The framework is described as "optimized for programmer happiness and sustainable productivity". It's great if this also leads to a design which is approachable for newcomers but I think it is a mistake to judge features as if that was the intent.