Usually when the term "Yankee" or "Yank" is used the intent is to separate the individual because of some trait that is not considered to be the norm. It could be something innocent as "those Yankees don't have good BBQ" but the implication is that we are deficient in some fashion.

In the earlier part of this thread, the word Yank was used to say that we Americans stole an English game and we are a bunch of girls for playing it. That bothers me. A little. Nothing to lose sleep over.

Again, it is minor and I don't think anyone would take serious offense to it - but it can be irritating.   The same thing with the word "redneck".   Terms that separate and isolate groups because of a geographic difference is the same as using a term that demeans people because of race or religion. I am sure that there are people reading this that are saying - there he goes, being too PC again. Maybe I am. If we can't fix the little things then the big things will never get fixed.