Your overall point has validity, though. The Turd-world-ization of America has many causes and will not be solved easily.
I doubt many of the kids in this case in Texas come from families where the income is under $100,000 a year.
Today families with money are not raising their kids with anything that resembles morals or manners. Of course the problem with wealthy young people being total louts is not a new one but the pressure of middle class morality kept it under control in the US.
That pressure is now being removed.
We are, I fear, going to have to embrace the Oxford Solution.