Agreed on the 'big numbers' play, but with regard to the Australians, their ship had to sail 2 days in the wrong direction, followed by almost another week back to Australia (which they had just left). Before setting off again on the original mission - so I think the additional cost was more than it might otherwise have been!
The issue is also that if you required them to have insurance (to cover these possible costs) then it would be unaffordable, and so still be a discouragement to try for the big goals...