indeed, it seems as if plunging fire from shells or bomb angles (again, plunging factor) did more to accelerate ship destruction than torpedoes. I would imagine it had something to do with minimal protection on horizontal surfaces, made only worse with what had to be a rather one-sided thought process on where the most damage would be received: vertical surfaces. It didn't help that the British had a very dangerous flaw in their turrets for loading the guns, something they took great pains not to repeat in the years after The Great War.
That said, look at any of the combat operations involving catastrophic sinkings by torpedo during WW2. Loss only seems to be great where procedures weren't followed (Taiho, Barham, Shinano, Indianapolis): Ark Royal, Eagle, and Wasp had fairly minimal casualties for the hits received.