And Also

The casual use of the word "retarded" (and its variations)  as a put down (e.g., "just don't say anything retarded like ____") is one of the reasons people like my brother are not treated as full members of society.

It equates intellectual disability with inferiority.

The two are not the same.

...as a matter of fact, just don't use that word at all, okay?

(Yes, this was prompted by something online -- something linked to by fandom_wank.  No, I'm not going to link to it directly, because it was all kinds of offensive, and I'm going to pretend I didn't read it in the first place.)