It's very clear: the one is a box full of electronics, the other is part of the central nervous system of a human being.

> but we all have training by looking at copywrited source code at some time.

That may be so, but not usually the copyrighted source code that we are trying to reproduce. And that's the bit that matters.

You can attempt to whitewash it but at its core it is copyright infringement and the creation of derived works.