France, like much of Europe, is well covered by towns and cities. So there is often not a great distance for emergency services to cover which means the cost of mounting a rescue will not be excessive.
As a counter point, Australia is sparsely populated. Apart from the coastal cities it is often hundreds of kilometers between towns or road houses. So the cost of mounting a land rescue can get into the tens of thousands of dollars.
Also there is a lot of ocean area for which Australia is the closest landmass. There have been numerous ocean rescues mounted from Australia for sailors competing in round the world races or record attempts, some of them soloists:
These rescues have cost hundreds to millions of dollars each and generally have been paid for by Australian tax payers as noted in some of the articles.
So yes it is nice that you will be rescued. But these people all put themselves in a dangerous position for their own entertainment/ego and needed rescue at great expense to others. The millions that were spent for some of the rescues needed to be diverted from services/programs that would have benefited the taxpayers.
The geographic and population distribution differences between countries means that some countries will end up with a larger bill than others for mounting such rescues.
For this guy trying to prove something by sailing the smallest boat, if he can't take out "rescue" insurance, he should not go. Alternatively, he could also arrange for a support vessel to follow close by in case he needs assistance.