Why are some americans so hard on mexicans,legal,illegal,or chicano?

I'm Boricua and from the east coast also. (I don't use s's though, not my fault.) Most of the people I know look down on Mexicans but I don't follow that crap. Mexicans come here and work harder than we do for the most part. Mexicans take jobs that the rest of us don't want, is that a bad thing? That should make them stand proud that we're a big bunch of sissies that think we're too good for certain jobs. Then we have the nerve to complain that Mexicans come here and take our jobs. BULLSH**!! We can have those same jobs and even more so because there's no language barrier. But like I said, we're too good for that. Then they get taken advantage of because they are paid below minimum wage, which is above what they can make back home. I say boo hoo to people that look down on Mexicans. I work in a hospital and deal with a lot of central american spanish people and for the most part, they are all extremely nice and respectful. Sorry for the other Bori's that treat you like crap. :(