The joke is "it's easy to break boards because they don't hit back." What if, instead of hitting back, the board just decided to not break? Even after multiple kicks, punches and cries of "COME ON YOU'RE MAKING ME LOOK BAD!!"

Finally, the board decides to fight back, but instead of attacking Mr. Super Kick, he takes a cheap shot at a little girl in the crowd. That'll show her! Go back to cheerleading!

After several failed attempts at breaking the board, Kung Fu Lou grabs a different board...who also knows he's a giant vagina with feet.