It's also problematic. For Shakespeare, and a lot of other writers up to the modern day, it is easy to give the villan a visible ailment that turns people off of them--in this case a hunchback. Disabled characters are often antagonists, because having an abnormal body is something that automatically--so the thought goes--repulses an audience, particularly an audience who did not understand disability.
At what point do we stop sanitizing things like this to change the image of disabiltiy in the world? Do we cut the lines to appeal to contemporary sensibilities and always cast an able-bodied actor? Or can Richard III be played by an actor with a disability without causing the negative connections?
Just a thought I had.