That's quite a theory. Wouldn't one expect to find other instances of such coercive omission? And yet, double-clicking a file in the Finder or Explorer still opens it in iTunes, which by default copies the track into your library. Ripping CDs still works the same. Drag and drop still works the same.

No, I think it has more to do with watch folders not being a feature in high demand than any conspiratorial nonsense.