It's a cultural change that has happened over the last few decades, but some have struggled to change with the times.
I grew up in a predominantly white area and didn't think nothing when I was younger of using the word chinkies for the local Chinese takeaway. It wasn't meant as a horrible reference to horrible people we didn't like, it's just the word we used.
Now, married to a woman who is half Hong Kong Chinese and half Malaysian I find the word horrible, but still understanding the word is common speak reference to Chinese. Just like Japs is to Japanese.
I find myself hypercritical on the issue because I have used both words, and I never said or thought them with menace or hatred like you could say with the N word for example, but it's still a word that time has passed by as something acceptable by the masses that reject their use.
What is difficult is when I head back to see the family and good friends still haven't quite got on the same boat regarding this though. I don't hate them for it, I can't, but it's uncomfortable at times.