If you write the failure path, then you also have to ensure it doesn't fire when there wasn't really a failure and do unnecessary heroics. Same reason you can'

If you write the failure path, then you also have to ensure it doesn't fire when there wasn't really a failure and do unnecessary heroics. Same reason you can't program a self driving car to save a person by sacrificing a squirrel. It's just going to run over the squirrel when it didn't need to.