Bookworm
Having stated that airmanship should protect a pilot against stall warner failure, let me now play devils advocate when you say "The failure that you're concerned about (stall warner fails to alert pilot to imminent disaster after electrical failure) would require two highly unlikely events: both the failure of the pilot to maintain a proper AoA and the failure of the electrical system."
I could make a strong argument that electrical failure is just the sort of distraction that could cause a single pilot to miss a change in AoA and get into trouble, especially if the pilot was inexperienced - so perhaps the holes in the cheese might align.