i agree with luvbeaches. and i do think that 'extreme' mountain climbers (for one) do have a certain addiction to high-stakes risk-taking, or need to push the limits of survival, some could say it's a chemical addiction. what do you wanna bet that if these guys were rescued, then asked, 'are you going to keep mountain climing?', they wouldn't have said, 'you betcha we will!' (which is what usually happens in these situations). that being said, i think that rescuers also are in love with the challenge of being able to find lost people, there is something in their brains that drives them too. so maybe they are cut from the same cloth. but they can only do so much.
let me put this another way: if someone were addicted to the high of jumping in front of a train- and back, just a second before it would hit them, and they did it 100 times, and got hit on the 100+1st time- i wouldn't be surprised, or see it as a great epic tragedy.