Just to put things right: there may be subsidies in France to operate flights to Overseas Departments, Overseas Territories and to Corsica, but these subsidies are in exchange for a minimum number of rotations per day/week - basically Public Service Obligations.
If I'm not mistaken, the same happens with Loganair to the Orkney and Shetlands...
Also, these French subsidies ARE official, not hidden (not something one might understand from some of the previous posts) and they are paid to a number of airlines - NOT only Air France and its franchises/subsidiaries. Their aim is to ensure that some far-flung parts of French territory are not left without air links just because the route is (slightly) unprofitable.
At least the French do have something akin to a public transport policy - which is more than Britain can say...
As for BA, give them the Sahara, and within two years, they'll have to import sand...