That's a problem with the euphemism treadmill, not with the word in question. Any word can have negative meaning if it is said with negative or hurtful intent. Whatever word is used to distinguish those with a mental disability from those who are just otherwise less intelligent will be used as a slur to refer to those who are just on average less intelligent. 'Downsie' is now used as a slur by young kids/teens. Do we change the name of Down's syndrome because the word is used as a pejorative? Then kids will start saying that 'Aww shit, little jimmy must have an extra chromosome!' Wait, they already do that. I don't see a solution to this problem other than become harder to offend.The way I've always seen/interpreted the issues with that word is that by equating the mental disability with stupidity, it's equating the people with that disability with something negative.