I'm well aware of the absurdity of the "FRENCH ALWAYS SURRENDERS!!1" fad, its origin comes about because there have been several wars where they entered and were utterly smashed within a year of engagement -- Franco-Prussian, WWII, Seventh Coalition, and the Agincourt campaign of the Hundred Years' War are the only ones I can think of. The fact that they're a great power makes this particularly odd, but it's by no means a pattern, and it should not eclipse all of the examples where France won wars when fighting practically alone against several other powers, such as the Nine Year's War or the League of Cambrai.
The 16th century is quite the fascinating one for France. She had not yet become the juggernaut under the Bourbons that could hold her own against all her neighbors combined. Nevertheless, in many of the Italian Wars she was encircled by the English, Germans and Spanish and managed to either win or end in a stalemate. (Though France also fared terribly in some of those conflicts, such as the 1521 Italian War that ended with the Battle of Pavia.)