Mathematically speaking, because compilation is a surjective function. Context, organizational, as well as personal knowledge - that information simply is lost in the process of compilation.
It can be restored to some extent by making educated guesses, but it'll never be exactly as readable as the original, which in some cases probably isn't that bad, because the original source code might not have been particularly readable to begin with.
It can be restored to some extent by making educated guesses, but it'll never be exactly as readable as the original, which in some cases probably isn't that bad, because the original source code might not have been particularly readable to begin with.