Dude, I copyed it off an american guys website, he's referring solely to americans.
Besides if someone comes from Mexican heritage, they're mexican-american.
If you're saying "they're just as american as us", well yes they are. But I doubt they want to shun their heritage >___>
I see where you're coming from though, but hey, you can't please everyone all the time.
Some take offence to Blacks, other take offence to African-American.
So I just call everyone people ^^