What's in a PC Name?

I think I figured out why the politically correct name for things changes kind of often. If we spoke kindly and lovingly of people groups, if the word for "those people" sounded like a grateful sigh in our mouths instead of something bitter or disgusting, there would be no need for changes. The terms wouldn't be considered derogatory. But instead, each term gathers negative associations as people use it disparagingly and link it to unpleasant newspaper headlines and unflattering scientific studies and controversial legislation, or simply to people they wish to insult.

Each societal group wants to be widely embraced (except for nonconformists or something, probably). In order to have the chance to be loved by all, the name by which they identify has to be free of the stain of connotations, the scent of scandal and disapproval. Thus, a new name is needed often. But you can't get rid of people's opinions just by changing the name of the situation, so fresh negative connotations build up and all too quickly it's time for a new change of name.

My dad used to tell me all the time about how the words moron and idiot (among others) used to simply indicate different levels of intellectual capacity. I know it's hard to imagine now, but they weren't disrespectful, and according to Wikipedia, there are still laws on the books today that prevent "idiots" from voting in Ohio, Kentucky, and other states.

I found these definitions on Wikipedia:
"Idiot indicated the greatest degree of intellectual disability, where the mental age is two years or less... The term was gradually replaced by the term profound mental retardation (which has itself since been replaced by other terms)"
"Imbecile indicated an intellectual disability less extreme than idiocy... It is now usually subdivided into two categories, known as severe intellectual disability and moderate intellectual disability"
"Moron was defined... as the term for an adult with a mental age between eight and twelve; mild intellectual disability is now the term for this condition."

"Retarded" used to be the most respectful term to use. It literally means "slowed down," which is not such a bad way to think of it in my opinion; we all travel at our own pace and "slow" doesn't necessarily mean "unsuccessful"--think of the tortoise and the hare. But people used the word "retarded" to describe whatever they disapproved of until it came to mean, more or less, "bad/stupid," and as a result it's extremely politically incorrect.

You cannot enforce kindness and respect by external means, and therefore it seems unlikely that this constant language-morphing will ever stop coming. I do think it's valuable to make a point of person-centered language, as it is a reminder of someone's humanity: their identity as a human before anything else. "Idiot," "imbecile," and "moron" were not replaced by new identifying nouns, but instead new terms to be used in conjunction with a personal word like child, person, woman, or man.