Look, there's PC and then there's ridiculousness. People who make the argument of "I don't have to be PC, you just need to stop being offended", I can safely say, are probably cis white males who have only ever maybe been called random insults because of relatively minor things. The word tranny offends me because I am trans, and said word has been used to belittle and mock me and people like me for decades, just like I'm sure Richard Sherman didn't appreciate hundreds of people on twitter calling him a nigger. Then you have people who get offended at the term Mexican, even though they're from Mexico. While I don't think the word Mexican should be used to describe someone of Hispanic origin when you don't know exactly where they hail from, the word Mexican is not, in and of itself, offensive. I know some people who get offended at the term "black people" and prefer "people of color", and I also know people who are fine with the prior term and refer to themselves as such.
In any case, my point is that in my opinion, it's good to be PC up to a point. You shouldn't be bending over backwards to please every single perceived minority, but a little common courtesy is nice to have.