Not acceptable #2: There's been too much real death in wrestling
Perhaps the biggest reason why pro wrestling companies should not use death as part of their storylines is the sad, tragic history of pro wrestlers dying young.
Most people will recall Owen Hart's fatal fall from the top of the Kansas City arena in 1999, and the way it deeply affected the pro wrestling industry. Owen Hart was far from the first man to die at a wrestling event. Bruiser Brody was stabbed to death in his locker room in Puerto Rico, and no one was ever convicted for the crime.
More recent, and more tragic, examples certainly exist, but it's not necessary to dwell upon them. What's important is to realize that with real-life death haunting the world of sports entertainment like a specter, having 'fake' death makes a mockery of the real world tragedy, and thus it should not be included as part of a storyline or angle.