The thing I don't understand is, even if it isn't an offensive word in America, how is it a positive term? The context people have given is still a negative one, even if it is for amusement... it is still has negative connotation for a derogatory purpose.
There is no positive spin you can give to the word Spastic or Spaz in America, because it has no positive meaning... so why use a descriptive word that can't be positively defended?
Stupid Hasbro.