> The pedantry of being angry at the US for being the only country that actually has the word "America" in its name

That is not the reason.

People say that Columbus discovered America. They don't mean the country, they mean the continent. The people in the continent of America are called Americans. About a century ago, US Americans came to view America as two continents.

Many countries still hold to America being a single continent, but there's no name for the people of America because US Americans stole it. The is very equivalent to how the EU is stealing Europe/European.