The worst part of it is, England basically gave nothing culturally to Great Britain, or the world.
Says the Scot speaking English
Chillout, man. This has been the case with every Civ game ever, and it's not just Americans, Europeans struggle with the difference sometimes as well. And at least Edinburgh's in the game this time, and other than the Civilopedia (which was probably written by someone other than the people who designed the factions) the Kingdom represented
is England before the personal union with Scotland when James VI/I took the throne. So other than the 'pedia text, which you can edit, it does represent the English Empire in the period of the first colonization of the Americas - which was a pretty important period.
And to be fair, if they did have the sense to choose Great Britain they'd have another problem - which Great Britain? If they went for the United Kingdom of Great Britain and Ireland and included Dublin and Belfast there'd be a hugggggggge fuss. If they went for the United Kingdom of Great Britain and Northern Ireland they'd pick the empire when it was at its greatest extent but beginning to decline. They're clearly not going to put that much thought into it, considering the game starts in 4000bc.
On top of that IV was full of other stupid errors. Victoria was not just Queen of Great Britain, but also the Empress of another civilization in the game - India. What about Russia? Why are they considered to be the same state as the Soviet Union? Why did China have a ruler from a Mongolian royal line? Why were the Eastern and Western Roman Empires represented in a game with Greece? Why is America called America (the name of a continent) when it should be called the United States of America to differentiate the US from other Americans (in fact, how many states does America represent in the game?)? Why was Constantinople and Istanbul in the same game? Oh yeah, cus it's just a game.
It's also ironic that people are annoyed that the success of English imperialism in claiming Scottish identity and achievements means Scotland isn't recognised for being, uhhh, a major player in the biggest empire ever. If I was Scottish I'd be annoyed that the Picts, Scots, and other celtic countries' success in resisting Roman and English expansion was being overlooked, rather than the fact that Scots helped the English collect slaves, bombard Americans, kill French people, "keep China British", etc etc.