France has far fewer hotspots than any of its European neighbors: In fact, it's on par with Slovenia in terms of number of hotspots.
It seems mostly the government is to blame. One conspiracy theory is that the government stands to benefit from the success of 3G networks so it wants to prevent Wi-Fi from becoming a competitor to those mobile networks. Government mandates, such as one that held until last November that prevented any Wi-Fi coverage outdoors for fear of interference with military operations, surely slowed down build out. Just last summer the government dropped to demand that municipalities get federal permission to hang APs.