We judge the world based on our own perspectives and our own level of experiences. If you hang around groups with a lot of English speaking Americans in it, you get a lot of people who don’t bother mentioning the country they’re in.
If you’re in a group of professors and students talking about linguistics and there’s a slightly heavier Russian population in the group, they’ll often drop the fact they’re from Russia from the conversations and just mention their cities and areas.
I think it’s more due to group dominance than certain nationalities though.
Then again, we’re taught a peculiar thing in the USA – one of our prejudices: We’re taught, if someone is from another country, we’ll be able to tell ‘somehow’ by their accent or by the words they use.
But online, there’s few distinguishing factors from one country to another in the words they choose.
So, our default is: If person writes “like an American”, must be an American.
Also, we’re NOT taught about American Imperialism as a _current thing_. I only recently realized it myself. We’re taught that American Imperialism WAS a phase of the USA in the 19th century.
What we’re NOT taught is that we’re CURRENTLY in a phase of American Imperialism.