The context of this discussion was kids in "ultra ghetto urban districts"
Not sure why we are talking about intellectually disabled kids. Someone else did this juxtaposition, and it is quite concerning that people tie poverty with lack of ability in this thread.
That reason is largely the euphemism treadmill, but I would grant that saying "ultra ghetto" is deliberately insensitive and no professional would use it to describe impoverished areas.
Origin was 1788 from my little research. Point is that all of these words start out as high-minded words from well-meaning people and then some ninny comes along and tries to change the word, telling everyone that their words are bad instead of looking at the problem square in the face, however ugly or bad the problem may seem.
1846 - Simpleton
~1876 - Feeble-minded
1910 - Moron
1900s Special Ed
1900s Intellectually Disabled
The label is useful. The condition is lamentable. Changing the label every few years doesn't make children not use the new one as an insult.
Using a new or old label doesn't positively imply that you hate the group or person you're applying the label to.