Why can't Mexicans see that they are basically looked at as the racist N word in this country too?

I just saw two Mexicans getting out of a cab, They looked to be drunk. The cab driver was of African dissent and even had an African accent. One of the Mexican guys spit inside of the cab before walking off. The cab driver asked him why did he spit in his cab like that, and the Mexican guy said f- u. This made the African cab driver mad, and he walked up to the Mexican guy and got in his face and said f-u back to him. I thought they were going to fight, but the Mexican guy's buddy played peace maker. Well after the arguing stopped and the Mexicans started to go on their way and once they were safely across the street , the Mexican guy that was arguing with the African cabbie, shouted the racist N word back at the cabbie. The cabbie kept his cool, and got in his cab and drove off. The question is, do they not know that they are called and seen as something similar to the racist N word too. Sometimes it is the racist N word.