It seems that France, more and more socialist at the time since 1929(?), didn't want to attack the socialist-communists: German National Socialists + URSS in 1939/40 because of their alliance. and that would be why the need to surrender was so important despite pretty-okay infantry, chars and generals.
What? France surrendered because they realized they would lose the war whatever they did. Also Vichy France was very much Catholic right-wing.