I don't really know...but I suspect it has something to do with France being a stronghold of SSPX. Remember when Papa raised the Good Shepherd Institute with a couple of ex-SSPX priests? The Institute mission is to accomodate seminarians and priests leaving SSPX and allows them to celebrate the Tridentine Mass. This was in Bordeaux...boy, did the Bishop howl. They said something about it being divisive.
Very possible. Of course, the only reason France was a hotbed of the SSPX in the first place was because of the behavior of the modernist French bishops...so I can see why they'd be upset. I just don't understand what power they have. Their churches are already empty and they are selling French churches to the Muslims - so who cares if the French bishops are annoyed?
That said, I know the Pope doesn't want to quench the smoking flax. Although I'm not sure they're even smoking any more, and obviously, most of the French don't think so either.