French speaking...
From my limited experience touring around France, its simply a matter of politeness to speak as much French as you can in order to fit in with the local traffic. It is absolutely pointless to rant about English being the laguage which they SHOULD be speaking. The fact is that if one wants to go there, and one has read the plate for the airfield noting the French must be spoken either all the time or outside of ATC's published hours, those are the rules, so play by them. There are plenty of larger airfields in France where English is spoken all the time so use those if your French is non-existent, or poor.
I am not particularly fluent in French, but seem to get by with a handful of phrases and by paying attention to the published procedures, the current wind, and keeping the good look out to avoid meatbombers, gliders and other circuit traffic.
I have often found that my French elicits English "clarification" from local pilots anyway, almost all of whom speak far better French than I speak English. Or, and this seems equally likely, one lands to find that you are the only traffic in the area anyway - yet another immaculate French airfield so under-used and so friendly particularly if you happen to be in need of some kind of assistance.
I don't personally think it is at all arrogant to insist upon French at some airfields. I wish it wasn't the case because it does cause me embarrassment at my lack of liguistic ability. But I cannot get upset about it. After all, it is my choice to want to go there in the first place...
SC