I agree that if you're looking at 4e and expecting it to be setting-neutral it won't deliver. It is not setting neutral. And it doesn't claim to be setting neutral. Pages 150-51 of the DMG are headed "The D&D World" and talk about the core premises of the setting, and what happens if you change them. This stuff is repeated in the Essentials books.
That's why I mentioned The Plane Above. 4e's alignment system doesn't make any sense outside of the particular setting context (which The Plane Above helps to elaborate). That's what I like about it. I think anchoring alignment in a particular cosmology which is at the centre of the game (and Basic also did this, with its Law vs Chaos conflict) is the only way to make alignment work.
On the other hand, I gather that the setting-rich character of 4e alignment is something you dislike about it.
I personally didn't have any trouble with this - I could supply a reason, and for me it harked back to Basic - but I agree in general that 4e would have benefitted from more and better designer notes.
