I don't see how the twitter example has anything to do with political correctness, and extremely sensitive artists are by no means a new phenomenon. As long as there have been art, there have been artists interpreting everything that isn't immediate praise as bullying, and others, often with artistic aspirations themselves, jump on because it means no one can criticize what they like either. I think this is more about artists with inflated egos and fandoms rather than any form of pc-culture.
I think it's worth remembering that whenever you think that pc-culture is stupid, the opposing side will do something even stupider. For example, in Sweden there's a treat made of butter, cacao, sugar and oatmeal rolled into a ball that's nowadays called
chocolate-ball, but in the 1950's they used to call it n-word ball. When this was changed for obvious reasons, lots of old people complained about the name change, but most people today do prefer the name that actually describe what the chocolate balls taste like and does't imply that the balls were created by castrating a black man.
Likewise, when several people wanted to expand the Swedish language by introducing a third, gender neutral pronoun, lots of people protested and put up tons of ridiculous straw-man arguments about "shall we be forced to burn all the old books with the old pronouns in them" and "kids won't be allowed to be girls and boys anymore", none of which ever happened when the third pronoun became popular. People in Sweden didn't stop using he or she as pronouns, most people simply discovered that having a gender-neutral pronoun is a good option to have for situations when you want to adress both men and women at the same time.
