Spread the Word to end The Word

Since the middle of my high school career ive been following this movement know as Spread the Word to End The Word. the word in question is Retard. im curious as to how this term has come to mean anything you think is dumb or useless. case in point " this movie is so retarded".  yes retarded. a word that by its true definition medically is used to describe a disorder that is beyond a person control. and now people feel its ok to take this word for a group of people with something outside of their control. when it comes down to it retarded is nothing more than a slur. in fact its worse than a simple slur. when a racist person says niger they are talking to a person. all they are doing is using the word niger to describe a person.
whenever someone uses retarded they take it even further, they take it past the point of the word niger. they are taking a word that applies to a group of people and then changing the meaning even further becuse they apply this word to mean that something is stupid and useless. so i urge you the next time you dare use the word to say something is stupid i want you to realize that you are calling autistic people , people with down syndrome, and any other physical or mental retardation stupid and useless. to me someone who calls something retarded is far worse than anyone who address a black man as a niger.