They sure as hell are not opting for the hard stuff. I can hardly find an American kid in a graduate engineering program. I know this for a fact. They all wanna be MBAs because you got to be the boss who doesnt have a clue as to how the product actually works...
Smart adults look at the data available to them. STEM talent is being imported and this cuts off career progression as well as inhibiting salary growth, meanwhile careers anchored in cultural literacy, such as marketing and PR are doing well.
I'm not disagreeing with you but I understand why this is happening. A typical career needs upwards progression - an engineer can start and then when he progresses and earns more he becomes too expensive to keep on and is let go when replaced by a Chinese engineer or an Iranian engineer hired for less.
Short term gain for the employer equals long term disruption in the labor pipeline.