Not to knock on many of the countries listed, France has a pretty big history and has impacted the world just as much as the other European countries. It also has a fairly distinct , unique, and romantic culture not found in many.
In addition, from my experiences living here in Japan, many Japanese absolutely live France. If say of all the European countries, France and Italy are the most famous. When I teach countries to my 6th graders, I usually see "I want to go to France" or "I want to go to Italy." I have never seen Germany, England, Spain, etc. I have taught at a total of 15 elementary schools and 10 junior high schools and I have noticed this trend. I think they wanted to focus on an European country that has a distinct culture. I agree they felt France what they were aiming at in XY but I also think that, in the Japanese perspective, France has a much more distinct and noticeable culture that they can adapt from compared to England (and not to knock on England; I would love to see it as a region.)
I'm just glad they are branching out into other areas of the world. Japan is great but I think expanding to other countries helps expand and diversify the Pokemon world.