The fundamental flaw of the 'leaseback' property is the reason the product was conceived in the first place: lack of tourism infrastructure in not-so-developed areas of France.
The most prosperous areas in the South are Cannes and Nice. You won't find leasebacks there.
On the other hand, I presume there are exceptions and cases where people will make a decent profit from this product. I wouldn't rely on it for the pension, though.