A couple of years ago someone died on a mountainbike trail I use. This can really spook people, even those of us who didn't know the guy. Ultimately people want that feeling to go away and be able to enjoy the sport without such things hanging over them. It felt like people wanted closure so that the fun could continue rather any deeper sentiment.

Also I think that these sport are about more than just adrenalin. There is joy in mastering the difficulty without getting a rush.