The concept of "political correctness" or as some people used to call it, "politeness", is that you don't set out to offend or use language that might unnecessarily offend if you can help it.
"Nigger" for example is often frowned upon. As is "paki", "chink", "coon" or "wog". In recent years, they have been joined by "queer", "lezza" and "homo", "midget", "cripple" and "spastic". Derivations or synonyms used to describe someone's natural state as if it were somehow less, inferior to that of the speaker, simply by being.
Often these terms may have originally been descriptive without any negative loading, but over time and through multiple uses in the school playground or the adult equivalent, languages changes and gathers invective.
The X-Men comics have often used allegory to address such prejudice, with "mutie" being the original epithet, with Kitty Pryde once comparing it on panel to the N-word, recently succeeded by "genefreak". But "mutant" has generally remained descriptive in the comics. Uncanny Avengers #5 seeks to change that…
There you go folks. We have to call them all "Alexes" now. It's political correctness gone mad!
Damn dirty Alexes.
Comics courtesy of Orbital Comics, London. Currently hosting an exhibition by Des Taylor.