That is true. But asphalt and concrete barriers are not so kind either yet auto racing is huge. Same is true for downhill skiing. And even sports like boxing or football (american) are huge despite, or perhaps even partially BECAUSE of their dangers.
And they are huge as SPECTATOR sports because people like bread and circuses. At least half the crowd at an auto race is hoping for a crash. Humans are pretty bloodthirsty creatures, and our media plays on and enhances that attribute.
Now, how do you make diving a spectator sport? More importantly, why would you WANT to? Why does EVERYTHING in our society have to gravitate to the XFL, WWE, reality television lowest common denominator? Why, every time people find something that offers respite from the hype-fest, some huckster comes seeking to destroy it?
Yes, I know why - money. People are such *****s.
Now this is not to say that a sport MUST be dangerous
Actually, according to Hemingway, by definition it must - everything else he said was just a game.
But I think it is also not as big a deterrent as we might think...
You just aren't going to be happy until there's a diving spectacle hosted by Jerry Springer with some diver calling himself "He hate me," are you?