Because France refused to be involved in the Iraq War which made people angry. It's just anti-French sentiment.
France have contributed to the military more than any other nation in world history. Army, Corps, Division, Brigade, Battalion, Regiment, Platoon, General, Brigadier, Colonel, Lieutenant, Sergeant - these are all French words. If people slag the French military they should think of their own words for their military ranks and organizations rather than copy theirs.
As far as WW2 is concerned, no country survived a German Blitzkrieg - the Russians luckily had the land mass to be able to retreat to the Urals. And as far as WW1 is concerned more French soldiers were killed - 1.3 million of them - which is actually more than the UK, USA, Canada, Australia and Italy combined.