What's your point, KK?
"Mexican" as a catch all term for brown people is maybe not the best. For one thing, it isn't accurate, and for another it leaves the impression with your audience that distinctions between "other" groups of people are insignificant and unworthy of your care and attention.
"Mexican" means "person from Mexico." Like "Kansan" means "person from Kansas" or "American" means "person from somewhere in the Americas." Googling "George Zimmerman" and seeing that his mother is Peruvian and not Mexican is a small chore that prevents this kind of carelessness. It also prevents you from looking like a dumb bad person.
Just food for thought!