I think a lot of the bitterness simply is the result of envy. Some hispanics can’t stand the fact that Texas is prosperous while Mexico is a failure by comparison. If Texas was a dump, they wouldn’t care so much, and their pride would not be wounded by feelings of inferiority either. It makes perfect sense to me that envy made the cut as one of the seven deadly sins.
Parts of Texas are dumps, which is especially the case the closer you get to Mexico.