Are we talking about the same France? France, one of Europes largest military powers which actually use their military in various conflicts around the globe?
Maybe their argument is that France has nothing to fear from anyone, so why the secrecy? Of course it's nonsense no matter how you spin it. All militaries love secrecy (except maybe the ones that are just for show, but I expect even the Swiss Guard in the Vatican has its secrets).
I'm guessing their comment is from the view of the French being "cheese eating, surrender monkeys", a view not supported by France's long military history. This view was supported, for at least a few years, by a Google "I feel lucky" search for "French military victories" taking you to a Google search mockup site which suggested "Maybe you mean: French military surrenders".
Apart from the fact that the view of France as "surrender monkeys" is nonsense, it also makes no sense as an argument that their military wouldn't be interested in secrecy.