I also agree that these crews are all big boys and should be able to make their own decisions. (any girls? that's another thread
However, there is no mistaking the lifetime status of having "I was crew on an Americas Cup race boat" on your resume. All will be involved in the sport to make a living for their lifetimes. Whether applying for a job at a sailing school, university coach or yacht club, that is extremely valuable. They are vulnerable to being in a position to have to take on whatever risk is presented to have that value.
(on a completely unrelated track, I've only met a few sailors over my lifetime that were AC crew. Ironically, each was somewhat of a jackwad. Not sure what to make of that.