Yes, BNW put France on the operating table and performed a double testiculectomy. They are now practically a blank slate civ with no ability. The way I see it, Poland is the new France. Except that Poland can't get their Liberty settler any earlier than anyone else. France was VERY good, being able to tear through policies. Now I only play them if I want to be at a disadvantage.
I'm sorry, that extent of exaggeration is particularly unhelpful to helping other players learn how to use BNW France as a civ. It seems the real issue is a misunderstanding on how the culture game works now.
Culture is tall-strat first, wide-approach second. You need to build tall in a culture civ to take advantage of the Guilds and production for Wonders. Later on, you need to go wide for the GW/archaeology slots.
Ancien Regime, is too old for the new mechanics present in the game. If France was already a culture civ, how does having +2

help later on in a culture victory? Mechanically, it cannot. Chateaus and "City of Lights" address that in still ensuring France is pumping out tourism and culture. Chateaus also help defensively, which is important for Culture civs.
Overall, the culture game relies on having a high population, something that all of BNW France's abilites address. Tradition is still a great tree, and now France is tailored towards Tradition vs. Liberty. The new trade routes can ensure that Paris is pumping out wonders and growing. The higher population ensures filling up market slots and population working the chateaus for gold.
Musketeers are still essential. Militaristic/Domination civs can win a culture game by sniping out the wonder-whore and taking on it's role while pumping out their own great works. Musketeers give a chance to strike at any other nearby civ for their great works or their wonders.
I can understand that in higher difficulties, France is weakened, but none of the civs are balanced around high difficulties.
You can lament the change, but it won't make a difference. France is no more a blank slate than Indonesia/Polynesia on Pangaea or Byzantines smack-dab in a tundra. It's not the same France anymore, so play it for what it's suppose to be, not for what it was.
TLDR: Let them eat cake!