Because Mexican Americans living in Texas border towns don't share the victim mentality of some of the urban Blacks that you're referring to.

Young Blacks today---especially the men---are taught that it's okay to live down to a certain stereotype because it's not their fault. And they often get this message from lily white liberals living in suburbia, but commuting to their inner city jobs as social workers and guidance counselors.

Zero accountability for who they are. Because it's all whitey's fault anyway. And let me be clear, not all Blacks are like this. But the demographic that you're referring to certainly fits the bill.