I have personal experience working with the French in various archives, museums & libraries in Paris & found them to be among the most polite, professional & respectful (and happy) people I have ever met. As for fighting, just the French partisans alone tells one that they could be lethal & fearless if given the chance.
You can't blame France for having a neighbor like pre-1945 Germany. Both Germany & Japan were warlike cultures that literally needed to be blasted back to the Stone Age to calm them the heck down & consider a new path.
I have to say that dissing the French and their fighting ability is a bit knuckle dragging neanderthal behavior, by people having concrete as the only grey matter between their ears.
Comparing the Battle of France to the Battle of Britain is apples & oranges. All the Western democracies were in dire straits in 1940. France, unlike Britain or the U.S., couldn't pick & choose their battles, and there was no room for error. Britain always had the luxury of American armaments & and America always had the benefit of two oceans.
Many reasons contribute to who wins wars.
After WW1 Britain hitched her wagon to the American train, and France never did & preferred to go their own way. Americans feeling #1, resent this.
Britain went to war with the Kaiser because of his Navy. Right after WW1 Britain found a new challenger, the American Navy, whom dearly had a score to settle with the British & drooled at the chance. Did the British maintain their stance of supremacy? No, they backed down & signed on to the Washington Naval treaty. They knew that if you can't beat them, join them.