I grew up taking things apart just so I could see how they were put together, and the concept of using "prefabs" without ever knowing what they're made of or how they work is anathema to me.
Edit: But I certainly get both your point and the point of the whole setup.
I understand your unease, but when you are dealing with systems containing hundreds of thousands of lines of code written in a style that is intentionally designed to make the internals invisible (
ie. Object Oriented) it quickly begins to make a lot of sense.