I’ve said it before, I’ll say it again, Robin is the one who freaks the bad guys out, probably more in some ways than Batman.
Batman is mean, Batman is scary, Batman has a glare that can sttrip paint off the wall, but he’s a grown man, built like an outhouse. He’s a threat because he’s a viable threat and a 6′7″ henchman will probably respect and understand that. Being beaten by Batman is no actual shame.
But his kid? The scrawny little squirt in the silly outfit? He’s just WEIRD.
You don’t see him at first, you just hear him giggle from somewhere near you, somewhere you can’t quite place and the next thing you know a jumping jack in a cape is somersaulting around the place, delivering four blows of random pain and dancing off in the time it takes you to pull your hand back into a fist.
Even an average thug will have a moral qualm or two about punching someone who is not only shorter than them but an actual, literal, child, someone whose voice hasn’t even broken yet, but somehow this 5′3″ twerp is HURTING you and he’s smiling the whole damn time.
There’s no recovering from the sort of shame that being beaten by someone who doesn’t even come up to your armpit in height.
Batman appears, beats you unconscious, and then fades out again. The Kid laughs, prolongs your embarassment for as long as he can, and then diappears, still laughing. Like I said, Robin would be DEEPLY unsettling.