He's making a mistake here. The "dregs" make up the majority of the Mexican population. He's seeing the typical Mexican as well-off or comfortable, when 51% of the population lives in poverty and another 20% lives in extreme poverty, according to the World Bank. You can't define a people based on 30% of its population.
I agree that's the mistake he's making too. The way Mexican culture and society is set up, no one works their way into any job or status --- it's very classist --- if you are born into the small upper class, your money and connections buy you a high paying job. What he's calling the dregs are those who were born poor -- the majority and are denied all opportunity and education -- in Mexico your birth determines your destiny. You can see that even here -- those from the upper class are often dumb-as-doorknobs but believe they are entitled to good jobs while those from the dregs are much more clever and quick -- but less educated because that's they way it works in Mexico.