How is it that Robin is "too stupid", but Spiderman, a teenage-adulthood superhero, works just fine on screen? Peter Parker and Richard Grayson are nearly the SAME THING. Acrobatic, Intelligent, wise-cracking, chick magnets. If one can work, so can the other. If you can accept that a kid gets powers from being bit by a spider, you can accept a tennager/young man following in Batmans footsteps.
BTW, why is Batmans fighting on screen still average?!? I never get the sense that he can beat the crap out of anyone, because he throws elbows and punches 99% of the time only. Wheres his freaking roundhouse kicks and crap. Is there any actor who looks like the part of Bruce Wayne and already knows martial arts?