For me, it's not the word (any word) but the intention behind it. When I was growing up "retarded" was the "special needs" change from "slow". As in, people were intentionally TRYING to use it to be kind. (To retard something, retard is or rather WAS a verb, means to slow it down). Of course, slow was the retarded/special needs from stupid, and stupid was the slow/retarded/special needs from, etc./so forth/ so on.
In 15-20 years Special Needs will be what Retarded is now. ((In fact, people are ALREADY scorning & using "Special Needs" as a derogative, especially middle & highschoolers, and it's 50/50 on the college campuses I've been on whether or not SN is a derogative word)). When SN becomes a pure insult, about 5 years will pass while people try and come up with a new non-associated word (remember the whole handi-capable thing?), and a bunch of words and phrases will get tried out, until one is chosen by general use / lack of mocking.
People (as a species) will always fear the unknown, strange, & unfamiliar. So there will always, always, always be bigots... who believe that only THEIR way is the right way.
Gee... I'm just the little bluebird of happiness, aren't I?
On the upside... people have been fighting bigotry, probably since it's invention. One of my favorite poems is by Rudyard Kipling, doing JUST that:
We & They
Father and Mother, and Me,
Sister and Auntie say
All the people like us are We,
And every one else is They.
And They live over the sea,
While We live over the way,
But-would you believe it? --They look upon We
As only a sort of They!
We eat pork and beef
With cow-horn-handled knives.
They who gobble Their rice off a leaf,
Are horrified out of Their lives;
While they who live up a tree,
And feast on grubs and clay,
(Isn't it scandalous? ) look upon We
As a simply disgusting They!
We shoot birds with a gun.
They stick lions with spears.
Their full-dress is un-.
We dress up to Our ears.
They like Their friends for tea.
We like Our friends to stay;
And, after all that, They look upon We
As an utterly ignorant They!
We eat kitcheny food.
We have doors that latch.
They drink milk or blood,
Under an open thatch.
We have Doctors to fee.
They have Wizards to pay.
And (impudent heathen!) They look upon We
As a quite impossible They!
All good people agree,
And all good people say,
All nice people, like Us, are We
And every one else is They:
But if you cross over the sea,
Instead of over the way,
You may end by (think of it!) looking on We
As only a sort of They!
Poor Kipling... he has dozens and dozens of poems trying to get people to look at things through the underdog's eyes, but terribly taught english lit classes all over the country he's maligned from coast to coast.